Duolingo (DUOL) 10-Q10 Nov 222022 Q3 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares	9 Months Ended
Cover Page - shares	Sep. 30, 2022	Nov. 09, 2022
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2022
Document Transition Report	false
Entity File Number	001-40653
Entity Registrant Name	Duolingo, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-3055872
Entity Address, Address Line One	5900 Penn Avenue
Entity Address, City or Town	Pittsburgh
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	15206
City Area Code	(412)
Local Phone Number	567-6602
Title of 12(b) Security	Class A common stock, $0.0001 per share
Trading Symbol	DUOL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Central Index Key	0001562088
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Amendment Flag	false
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		31,279,319
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		8,890,418

UNAUDITED CONDENSED CONSOLIDATE

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 599,967	$ 553,922
Accounts receivable	30,197	33,163
Deferred cost of revenues	30,258	24,219
Prepaid expenses and other current assets	7,909	7,967
Total current assets	668,331	619,271
Assets, Noncurrent
Property and equipment, net	13,191	8,211
Capitalized software, net	7,018	4,566
Operating lease right-of-use assets	23,150	28,369
Deferred tax assets	418	0
Other assets	1,591	894
Total assets	713,699	661,311
Current liabilities
Accounts payable	3,363	7,818
Deferred revenues	134,944	98,267
Income tax payable	145	113
Accrued expenses and other current liabilities	17,178	12,933
Total current liabilities	155,630	119,131
Liabilities, Noncurrent
Long-term obligation under operating leases	24,243	29,124
Total liabilities	179,873	148,255
Commitments and contingencies (Note 8)
Stockholders’ equity
Common stock, $0.0001 par value; 2,000,000 shares of Class A common stock authorized and 31,176 issued and outstanding at September 30, 2022; 30,000 shares of Class B common stock authorized and 8,910 issued and outstanding at September 30, 2022; 2,000,000 shares of Class A common stock authorized and 16,645 issued and outstanding at December 31, 2021; 30,000 shares of Class B common stock authorized and 21,627 issued and outstanding at December 31, 2021	4	4
Additional paid-in capital	750,380	683,966
Accumulated deficit	(216,558)	(170,914)
Total stockholders’ equity	533,826	513,056
Total liabilities, convertible preferred stock and stockholders' equity	$ 713,699	$ 661,311

UNAUDITED CONDENSED CONSOLIDA_2

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common Class A
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, shares issued (in shares)	31,176,000	16,645,000
Common stock, shares outstanding (in shares)	31,176,000	16,645,000
Common Class B
Common stock, shares authorized (in shares)	30,000,000	30,000
Common stock, shares issued (in shares)	8,910,000	21,627
Common stock, shares outstanding (in shares)	8,910,000	21,627

UNAUDITED CONDENSED CONSOLIDA_3

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Revenues	$ 96,065	$ 63,595	$ 265,671	$ 177,758
Cost of revenues	26,302	18,078	71,661	49,234
Gross profit	69,763	45,517	194,010	128,524
Operating expenses:
Research and development	41,976	29,345	105,974	73,814
Sales and marketing	17,721	15,267	47,938	44,659
General and administrative	30,228	29,605	87,141	52,643
Total operating expenses	89,925	74,217	241,053	171,116
Loss from operations	(20,162)	(28,700)	(47,043)	(42,592)
Other income (expense), net	1,770	(219)	1,621	43
Loss before provision for income taxes	(18,392)	(28,919)	(45,422)	(42,549)
Provision for income taxes	53	51	222	69
Net loss	(18,445)	(28,970)	(45,644)	(42,618)
Net comprehensive loss	$ (18,445)	$ (28,970)	$ (45,644)	$ (42,618)
Net loss per share attributable to Class A and Class B common stockholders, basic (in usd per share)	$ (0.46)	$ (0.98)	$ (1.16)	$ (2.29)
Net loss per share attributable to Class A and Class B common stockholders, diluted (in usd per share)	$ (0.46)	$ (0.98)	$ (1.16)	$ (2.29)

UNAUDITED CONDENSED CONSOLIDA_4

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Convertible preferred stock beginning balance (in shares) at Dec. 31, 2020	19,074
Convertible preferred stock beginning balance at Dec. 31, 2020	$ 182,609
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering (in shares)	(19,074)
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	$ (182,609)
Convertible preferred stock ending balance (in shares) at Sep. 30, 2021	0
Convertible preferred stock ending balance at Sep. 30, 2021	$ 0
Beginning balance (in shares) at Dec. 31, 2020		12,794
Beginning balance at Dec. 31, 2020	(80,691)	$ 1	$ 30,087	$ (110,779)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Issuance of common stock in connection with initial public offering, net of underwriting discounts and issuance costs (in shares)		4,466
Issuance of common stock in connection with the initial public offering, net of underwriting discounts and issuance costs	426,192	$ 1	426,191
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering (in shares)		19,074
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	182,609	$ 2	182,607
Stock-based compensation	26,120		26,120
Stock options exercised (in shares)		1,134
Stock options exercised	7,322		7,322
Common stock repurchased and retired (in shares)		(23)
Common stock repurchased and retired	(868)		(868)
Options repurchased	(7,335)		(7,335)
Net loss	(42,618)			(42,618)
Ending balance (in shares) at Sep. 30, 2021		37,445
Ending balance at Sep. 30, 2021	$ 510,731	$ 4	664,124	(153,397)
Convertible preferred stock beginning balance (in shares) at Jun. 30, 2021	19,074
Convertible preferred stock beginning balance at Jun. 30, 2021	$ 182,609
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering (in shares)	(19,074)
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	$ (182,609)
Convertible preferred stock ending balance (in shares) at Sep. 30, 2021	0
Convertible preferred stock ending balance at Sep. 30, 2021	$ 0
Beginning balance (in shares) at Jun. 30, 2021		13,271
Beginning balance at Jun. 30, 2021	(93,777)	$ 1	30,649	(124,427)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Issuance of common stock in connection with initial public offering, net of underwriting discounts and issuance costs (in shares)		4,466
Issuance of common stock in connection with the initial public offering, net of underwriting discounts and issuance costs	426,192	$ 1	426,191
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering (in shares)		19,074
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	182,609	$ 2	182,607
Stock-based compensation	20,662		20,662
Stock options exercised (in shares)		634
Stock options exercised	4,015		4,015
Net loss	(28,970)			(28,970)
Ending balance (in shares) at Sep. 30, 2021		37,445
Ending balance at Sep. 30, 2021	$ 510,731	$ 4	664,124	(153,397)
Convertible preferred stock beginning balance (in shares) at Dec. 31, 2021	0
Convertible preferred stock beginning balance at Dec. 31, 2021	$ 0
Convertible preferred stock ending balance (in shares) at Sep. 30, 2022	0
Convertible preferred stock ending balance at Sep. 30, 2022	$ 0
Beginning balance (in shares) at Dec. 31, 2021		38,272
Beginning balance at Dec. 31, 2021	513,056	$ 4	683,966	(170,914)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Stock-based compensation	$ 53,188		53,188
Stock options exercised (in shares)	1,585	1,585
Stock options exercised	$ 13,226		13,226
Release of restricted stock units (in shares)		229
Release of restricted stock units	0
Net loss	(45,644)			(45,644)
Ending balance (in shares) at Sep. 30, 2022		40,086
Ending balance at Sep. 30, 2022	$ 533,826	$ 4	750,380	(216,558)
Convertible preferred stock beginning balance (in shares) at Jun. 30, 2022	0
Convertible preferred stock beginning balance at Jun. 30, 2022	$ 0
Convertible preferred stock ending balance (in shares) at Sep. 30, 2022	0
Convertible preferred stock ending balance at Sep. 30, 2022	$ 0
Beginning balance (in shares) at Jun. 30, 2022		39,587
Beginning balance at Jun. 30, 2022	528,219	$ 4	726,328	(198,113)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Stock-based compensation	20,488		20,488
Stock options exercised (in shares)		379
Stock options exercised	3,564		3,564
Release of restricted stock units (in shares)		120
Release of restricted stock units	0
Net loss	(18,445)			(18,445)
Ending balance (in shares) at Sep. 30, 2022		40,086
Ending balance at Sep. 30, 2022	$ 533,826	$ 4	$ 750,380	$ (216,558)

UNAUDITED CONDENSED CONSOLIDA_5

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net loss	$ (45,644)	$ (42,618)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	3,426	1,969
Stock-based compensation	53,188	26,120
Changes in assets and liabilities:
Deferred revenue	36,677	25,668
Accounts receivable	2,966	(287)
Deferred cost of revenues	(6,039)	(6,141)
Prepaid expenses and other current assets	(2,154)	(2,559)
Accounts payable	(3,864)	6,512
Accrued expenses and other current liabilities	4,269	409
Noncurrent assets and liabilities	(777)	(335)
Net cash provided by operating activities	42,048	8,738
Cash flows from investing activities:
Capitalized software	(3,959)	(2,035)
Purchase of property and equipment	(5,270)	(3,063)
Net cash used for investing activities	(9,229)	(5,098)
Cash flows from financing activities:
Issuance of common stock in connection with the initial public offering, net of underwriting discounts and issuance costs	0	426,191
Proceeds from exercise of stock options	13,226	7,322
Repurchases of stock options	0	(7,335)
Repurchase of common stock	0	(868)
Net cash provided by financing activities	13,226	425,310
Net increase in cash and cash equivalents	46,045	428,950
Cash and cash equivalents - Beginning of period	553,922	120,490
Cash and cash equivalents - End of period	599,967	549,440
Supplemental disclosure of cash flow information:
Cash paid for interest	0	0
Cash paid for income taxes	608	94
Supplemental disclosure of noncash operating activities:
Implementation costs for cloud computing included in Current liabilities	0	27
Supplemental disclosure of noncash investing activities and financing activities:
Capitalized software included in Current liabilities	8	337
Property and equipment included in Current liabilities	45	2
Landlord incentives included in Prepaid expenses and other current assets	$ 2,148	$ 0

DESCRIPTION OF THE BUSINESS AND

DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION	9 Months Ended
DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION	DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION Duolingo, Inc. (the “Company” or “Duolingo”) was formed on August 18, 2011 and the Duolingo app was launched to the general public on June 19, 2012. The Company’s headquarters are located in Pittsburgh, Pennsylvania. On July 30, 2021, Duolingo completed its Initial Public Offering (“IPO”) of 5,872 shares of its Class A common stock at a price to the public of $102.00 per share, 4,466 of which were sold by the Company and 1,406 of which were sold by certain selling stockholders, which includes the exercise in full by the underwriters of their option to purchase from the Company an additional 766 shares of the Company’s Class A common stock. The gross proceeds to the Company from the IPO were $455,532, before deducting underwriting discounts and commissions and offering expenses payable by the Company. The Company did not receive any proceeds from the sale of shares of Class A common stock in the offering by the selling stockholders. Duolingo is a US-based language-learning website and mobile app, as well as a digital language proficiency assessment exam. The Company has a freemium business model: the app and the website are accessible free of charge, although Duolingo also offers a premium service, Super Duolingo (formerly called Duolingo Plus), for a subscription fee. As of the date of this filing, Duolingo offers courses in over 40 different languages, including Spanish, English, French, German, Italian, Portuguese, Japanese and Chinese. We have locations in the United States, China and Germany. Principles of Consolidation —The Unaudited Condensed Consolidated Financial Statements include the accounts of the Company and subsidiaries over which the Company has control. All intercompany transactions and balances have been eliminated. Basis of Presentation —The accompanying Unaudited Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) from the Company’s accounting records and reflect the consolidated financial position and results of operations for the three and nine months ended September 30, 2022 and 2021. Unless otherwise specified, all dollar amounts are referred to in thousands. The Unaudited Condensed Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such SEC rules. We believe that the disclosures made are adequate to make the information presented not misleading. In our opinion, all adjustments considered necessary for a fair presentation of the financial statements have been included, and all adjustments are of a normal and recurring nature. We consistently applied the accounting policies consistent with the annual consolidated financial statements elsewhere in this Quarterly Report on Form 10-Q, in preparing these Unaudited Condensed Consolidated Financial Statements. These Unaudited Condensed Consolidated Financial Statements should be read in conjunction with the audited financial statements and the notes for the fiscal year ended December 31, 2021 included in the Annual report on Form 10-K and filed with the SEC.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Sep. 30, 2022
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIESUnder the JOBS Act, emerging growth companies also can delay adopting new or revised accounting standards until such time as those standards would otherwise apply to private companies. While we have not historically delayed the adoption of new or revised accounting standards until such time as those standards would apply to private companies, we have elected to take advantage of this extended transition period and, as a result, our operating results and financial statements in the future may not be comparable to the operating results and financial statements of companies who have adopted the new or revised accounting standards. Accounting Principles —The Unaudited Condensed Consolidated Financial Statements and accompanying notes are prepared in accordance with GAAP. Use of Estimates— The preparation of Unaudited Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Unaudited Condensed Consolidated Financial Statements and accompanying notes. Significant estimates and assumptions reflected in the Unaudited Condensed Consolidated Financial Statements include, but are not limited to, useful lives of property and equipment, valuation of deferred tax assets and liabilities, stock-based compensation, common stock valuation, operating lease right-of-use assets and liabilities, capitalization of internally developed software and associated useful lives and contingent liabilities. Actual results may differ materially from such estimates. Management believes that the estimates, and judgments upon which they rely, are reasonable based upon information available to them at the time that these estimates and judgments are made. To the extent that there are material differences between these estimates and actual results, the Company’s Unaudited Condensed Consolidated Financial Statements will be affected. Cash and Cash Equivalents— Cash consists primarily of cash on hand and bank deposits. Cash equivalents consist primarily of money market accounts with maturities of three months or less at the date of acquisition and are stated at cost, which approximates fair value. The Company maintains cash deposits with financial institutions that may exceed federally insured limits at times. The following table shows the breakout between cash and money market funds. September 30, December 31, Cash $ 87,248 $ 44,165 Money market funds 512,719 509,757 Total $ 599,967 $ 553,922 The Money market funds are considered Level 1 financial assets. Level 1 financial assets use inputs that are the unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date. Advertising Costs — Advertising costs were approximately $12,807 and $12,013 for the three months ended September 30, 2022 and 2021, respectively, and $34,354 and $31,764 for the nine months ended September 30, 2022 and 2021, respectively, and are included within Sales and marketing in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss. Income Taxes— The Company’s provision for income taxes is computed by using an estimate of the annual effective tax rate, adjusted for discrete items taken into account in the relevant period, if any. Each quarter, the annual effective income tax rate is recomputed and if there are material changes in the estimate, a cumulative adjustment is made. Concentration of Credit Risk —The Company’s concentration of credit risk relates to financial institutions holding the Company’s cash and cash equivalents and platforms with significant accounts receivable balances and revenue transactions. The Company maintains cash deposits with financial institutions that may exceed federally insured limits at times. Management believes that the financial institutions that hold the Company’s deposits are financially credit worthy and, accordingly, minimal credit risk exists with respect to those balances. The majority of our revenue comes through our subscriptions and advertising streams and payments are made to Duolingo through service providers. The top two, Apple and Google, accounted for 54.6% and 26.6% of total Accounts receivable as of September 30, 2022, respectively. The top three service providers, Apple, Google and Stripe, accounted for 51.1%, 27.9% and 10.1% of total Accounts receivable as of December 31, 2021, respectively. Two service providers, Apple and Google, processed 55.2% and 27.7%, and 53.4% and 28.4% of total Revenues for the three and nine months ended September 30, 2022, respectively. Three services providers, Apple, Google, and Stripe, processed 51.6%, 29.3% and 12.1%, and 51.2%, 29.0% and 11.0% of total Revenues for the three and nine months ended September 30, 2021, respectively. Impairment of long-lived assets— The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If the sum of the estimated undiscounted future cash flows expected to result from the use and eventual disposition of an asset is less than the carrying amount of the asset, an impairment loss is recognized. Measurement of an impairment loss is based on the fair value of the asset. No assets were impaired during the three and nine months ended September 30, 2022 and 2021. Recently Issued Pronouncements Not Yet Adopted There are no recently issued accounting pronouncements that the Company has not yet adopted that they believe are applicable or would have a material impact on the financial statements of the Company.

REVENUE

REVENUE	9 Months Ended
REVENUE	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE The Company has three predominant sources of revenues; time-based subscriptions, in-app advertising placement by third parties, and the Duolingo English Test. Revenue is recognized upon transfer of control of promised products or services to users in an amount that reflects the consideration the Company expects to receive in exchange for those services. The Company does not enter into contracts with a customer that contain multiple promises that result in multiple performance obligations. Revenue is recorded net of taxes assessed by a government authority that are both imposed on and concurrent with specific revenue transactions between us and our users. Revenue from time-based subscriptions includes a stand-ready obligation to provide hosting services that are consumed by the customer over the subscription period. Users can purchase Duolingo monthly or they can purchase a six-month or year-long subscription and pay for the subscription at the time of purchase. Under the year-long subscription, users can also purchase a single plan or a family plan. The family plan includes up to six users on one subscription. Such payments are initially recorded to deferred revenue. The user has the ability to download limited content offline. However, as there is a significant level of integration and interdependency with the online functionality, the Company considers the service to be a single performance obligation for the online and offline content. The Company enters into arrangements with advertising networks to monetize the in-app advertising inventory. Revenue from in-app advertising placement is recognized at a point in time when the advertisement is placed and is based upon the amount received. Duolingo English Test revenue is generally recognized once the tests have gone through the proctoring process and a certification decision has been made. This process usually takes less than 48 hours after the test has been completed and uploaded. Customers have 21 days from the date of purchase to take the exam or their purchase will expire and revenue will be recognized. Virtually all customers complete their exams prior to expiration. Sometimes organizations may purchase tests in bulk via coupons with a one year expiration date. The Company will defer revenue from all tests that haven’t been proctored nor expired. The Company’s users have the option to purchase consumable in-app virtual goods. The Company recognizes revenue over the period in which the user consumes the virtual good, which is generally within a month. Principal Agent Considerations —The Company makes its application available to be downloaded through third-party digital distribution service providers. Users who purchase subscriptions also pay through the respective app stores. The Company evaluates the purchases via third-party payment processors to determine whether its revenues should be reported gross or net of fees retained by the payment processor. The Company is the principal in the transaction with the end user as a result of controlling, hosting, and integrating the delivery of the virtual items to the end user. The Company records revenue gross as a principal and records fees paid to third-party payment processors as Cost of revenues. Contract Balances —Deferred revenue mostly consists of payments we receive in advance of revenue recognition, and is mostly related to time-based subscriptions, which will be recognized into revenue over the course of the upcoming year (recognized over 12 months or less). Additionally, the Duolingo English Test has deferred revenue related to tests that have been purchased, but will not be recognized until the tests have been proctored. Disaggregation of Revenue In accordance with Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers , the Company disaggregates revenue from contracts with customers into source of revenue, which most closely depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. Information regarding source of revenues: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Over time $ 72,172 $ 46,030 $ 195,376 $ 129,587 Point in time 23,893 17,565 70,295 48,171 Total revenue $ 96,065 $ 63,595 $ 265,671 $ 177,758 Information regarding revenue by stream: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Revenues: Subscription $ 72,172 $ 46,030 $ 195,376 $ 129,587 Advertising 10,619 9,029 33,585 27,360 Duolingo English Test 8,192 6,695 24,308 16,563 Other (1) 5,082 1,841 12,402 4,248 Total revenues $ 96,065 $ 63,595 $ 265,671 $ 177,758 ________________ (1) Other revenue is mainly comprised of in-app purchases of virtual goods. Changes in deferred revenues were as follows: Nine Months Ended September 30, 2022 2021 Beginning balance—January 1 $ 98,267 $ 54,792 Amount from beginning balance recognized into revenue (89,387) (51,254) Recognition of deferred revenue (122,527) (83,088) Deferral of revenue 248,591 160,010 Ending balance—September 30 $ 134,944 $ 80,460

PROPERTY and EQUIPMENT, net

PROPERTY and EQUIPMENT, net	9 Months Ended
PROPERTY and EQUIPMENT, net	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
PROPERTY and EQUIPMENT, net	PROPERTY and EQUIPMENT, net Property and equipment consists of the following as of September 30, 2022 and December 31, 2021: September 30, December 31, 2021 Leasehold improvements $ 15,602 $ 10,258 Furniture, fixtures and equipment 4,942 3,053 Total property and equipment 20,544 13,311 Less: accumulated depreciation (7,353) (5,100) Total property and equipment, net $ 13,191 $ 8,211 Depreciation expense of $1,000 and $2,253 for the three and nine months ended September 30, 2022, respectively, and $545 and $1,485, for the three and nine months ended September 30, 2021, respectively is recorded in the Company’s Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss. Depreciation expense is included within the following financial statement line items within the Company’s Unaudited Condensed Consolidated Financial Statements. Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2022 2021 2022 2021 Research and development $ 627 $ 99 $ 1,224 $ 133 Sales and marketing 78 13 156 17 General and administrative 295 433 873 1,335 Total $ 1,000 $ 545 $ 2,253 $ 1,485

CAPITALIZED SOFTWARE, net

CAPITALIZED SOFTWARE, net	9 Months Ended
CAPITALIZED SOFTWARE, net	Sep. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
CAPITALIZED SOFTWARE, net	CAPITALIZED SOFTWARE, net Capitalized software consists of the following as of September 30, 2022 and December 31, 2021: September 30, December 31, 2021 Capitalized software $ 14,769 $ 11,144 Less: accumulated amortization (7,751) (6,578) Capitalized software, net $ 7,018 $ 4,566 Amortization expense of $482 and $1,173 for the three and nine months ended September 30, 2022, respectively, and $188 and $484 for the three and nine months ended September 30, 2021, respectively, is recorded in the Company’s Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss. Amortization expense is included within the following financial statement line items within the Company’s Unaudited Condensed Consolidated Financial Statements. Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2022 2021 2022 2021 Cost of revenues $ 274 $ — $ 547 $ — Sales and marketing 208 188 626 484 Total $ 482 $ 188 $ 1,173 $ 484

INCOME TAXES

INCOME TAXES	9 Months Ended
INCOME TAXES	Sep. 30, 2022
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The income tax provision for interim periods is comprised of tax on ordinary income (loss) provided at the most recent projected annual effective tax rate (“PAETR”), adjusted for the tax effect of discrete items. Management estimates the PAETR each quarter based on the forecasted annual pretax income or (loss). The Company is required to reduce deferred tax assets by a valuation allowance if, based on all available evidence, it is considered more likely than not that some portion or all of the benefit of the deferred tax assets will not be realized in future periods. The Company also records the income tax impact of certain discrete, unusual or infrequently occurring items including changes in judgment about valuation allowances and effects of changes in tax laws or rates, in the interim period in which they occur. The actual year-to-date income tax expense is the product of the most current PAETR and the actual year-to-date pretax income (loss) adjusted for any discrete tax items. Items unrelated to current period ordinary income or (loss) are recognized entirely in the period identified as a discrete item of tax. The income tax expense for a particular quarter, except for the first quarter, is the difference between the year-to-date calculation of income tax expense and the year-to-date calculation for the prior quarter. Items unrelated to current period ordinary income or (loss) are recognized entirely in the period identified as a discrete item of tax. The inclusion of discrete items in a particular quarter can cause the actual effective rate for that quarter to vary significantly from the PAETR. Therefore, the actual effective income tax rate for a particular quarter can vary significantly based upon the jurisdictional mix and timing of actual earnings compared to projected annual earnings, permanent items, earnings for those jurisdictions that maintain a valuation allowance, tax associated with jurisdictions excluded from the PAETR calculation and discrete items. Effective Tax Rate The effective income tax rate was (0.3)% and (0.2)% for the three months ended September 30, 2022 and 2021, respectively. The effective income tax rate for the nine months ended September 30, 2022 and 2021 was (0.5)% and (0.2)%, respectively. The year over year changes in the rate are primarily due to the impact of a discrete tax expense recorded in the second quarter. The effective income tax rate was lower than the US federal statutory rate of 21.0% primarily due to the impact of maintaining a US valuation allowance provided on US deferred tax assets. The Company continues to maintain a full valuation allowance on US federal and state net deferred tax assets for the period ending September 30, 2022 as a result of pre-tax losses incurred since the Company’s inception in early 2012. The Company is projecting pre-tax loss in 2022. In the second quarter, the Company established a deferred tax asset of $418 with respect to its China subsidiary. The Company has evaluated the realizability of this deferred tax asset and as it is expected, on a more-likely-than-not basis, to be fully realized, no valuation allowance was recorded against it. Current and Prior Period Tax Expense

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
STOCK-BASED COMPENSATION	Sep. 30, 2022
Equity [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION Prior to the IPO, the Company granted options to purchase shares of the Company’s common stock and restricted stock units (“RSU”) in respect of shares of the Company’s common stock to employees, directors and consultants under the Company’s 2011 Equity Incentive Plan. In July 2021, Duolingo adopted the 2021 Incentive Award Plan (“2021 Plan”) and the 2021 Employee Stock Purchase Plan (“ESPP”), each of which became effective on July 26, 2021 in connection with the IPO. An aggregate of 7,946 shares and 1,119 shares of Class A common stock were made available for future issuance under the 2021 Plan and ESPP, respectively. On each January 1, the number of shares of the Company’s Class A common stock available for issuance under the 2021 Plan have been, and through January 1, 2031, will be, increased by the lesser of (i) 5% of the shares outstanding on the preceding December 31 (calculated on an as-converted basis) and (B) such smaller number of shares of common stock as determined by the Board or the Committee (as defined in the 2021 Plan). On January 1, 2022, the 2021 Plan and ESPP were increased by 1,913 shares and 166 shares, respectively. The Company’s stock options vest based on terms in the stock option agreements, which generally provide for vesting over four years based on continued service to the Company and its subsidiaries. Each option has a term of ten years. Stock options granted under the 2021 Plan must generally have an exercise price of not less than the estimated fair market value of the underlying Class A common stock at the date of the grant. No options have been granted under the 2021 Plan. A summary of stock option and RSU activity under the Plans was as follows: Number of Weighted- Weighted- average remaining contractual life (years) Aggregate intrinsic value Options outstanding at January 1, 2022 6,255 $ 12.53 6.92 $ 585,339 Granted — — Exercised (1,585) 8.34 Repurchased — — Forfeited and expired (95) 16.82 Options outstanding at September 30, 2022 4,575 $ 13.89 6.49 $ 372,206 Options exercisable at September 30, 2022 3,671 $ 12.78 6.22 $ 302,468 The total intrinsic value of options exercised was approximately $129,725 and $102,628 for the period ended September 30, 2022 and 2021, respectively. Restricted stock units Weighted- Outstanding at January 1, 2022 730 $ 77.09 Granted 1,415 92.10 Released (229) 78.44 Forfeited (62) 80.08 Outstanding at September 30, 2022 1,854 $ 88.28 As of September 30, 2022, there was approximately $6,955 of unrecognized compensation cost related to stock options granted under the plans with a weighted-average period of approximately two years. The amount of unrecognized compensation expense for RSUs as of September 30, 2022 was $154,113 with a weighted-average period of approximately three years, for a total unrecognized compensation expense of $161,068. There were 8,409 shares available for grant at September 30, 2022. Performance-based RSUs In June 2021, the Company granted an aggregate of 1,800 performance-based RSUs (the “Founder Awards”) to the Company’s founders. The Founder Awards vest upon the satisfaction of both a service-based condition and a performance-based condition and generally are settled 1 year after vesting. The service-based condition is satisfied as to 25% of the Founder Awards on each anniversary of the completion of the IPO, subject to the continuous service of the founders through the applicable date. The performance-based condition will be satisfied with respect to each of 10 equal tranches only if the trailing 60-calendar day volume-weighted-average closing trading price of the Company’s Class A common stock reaches certain stock-price hurdles for each such tranche, as set forth below, over a period of 10 years from the date of grant. Any RSUs associated with stock-prices hurdle not achieved by the tenth anniversary of the date of grant will terminate and be canceled for no additional consideration to the founders. The stock-price hurdles and number of RSUs eligible to vest will be adjusted to reflect any stock splits, stock dividends, combinations, reorganizations, reclassifications, or similar events under the 2021 Plan. The Founder Awards will be settled in shares of the Company’s Class B common stock. Tranche Company Stock Price Hurdle Number of RSUs Eligible to Vest 1 $ 127.50 90 2 $ 153.00 90 3 $ 178.50 90 4 $ 204.00 180 5 $ 255.00 180 6 $ 306.00 180 7 $ 357.00 180 8 $ 408.00 180 9 $ 612.00 270 10 $ 816.00 360 The Company estimated the grant date fair value of the Founder Awards using a model based on multiple stock-price paths developed through the use of a Monte Carlo simulation that incorporates into the valuation the possibility that the stock-price hurdles may not be satisfied. The weighted-average grant date fair value of the Founder Awards was estimated to be $61.56 per share and the Company estimates that it will recognize total stock-based compensation expense of approximately $110,817 over the derived service period of each of the ten separate tranches which is between 3.58 – 5.92 years. If the stock-price hurdles are met sooner than the requisite service period, the stock-based compensation expense will be adjusted to prospectively recognize the remaining expense over the remaining derived service period. Provided that the founders continue to provide services to the Company, stock-based compensation expense is recognized over the derived service period, regardless of whether the stock-price hurdles are achieved. The stock-price hurdles for the first two tranches were met during 2021. No additional stock-price hurdles were met during the nine months ended September 30, 2022. The Company recognized $7,572 and $23,699 of stock-based compensation expense related to these awards for the three and nine months ended September 30, 2022, respectively, which is included within General and administrative in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss. As of September 30, 2022, there is $70,656 of unrecognized compensation expense related to these awards. Total stock-based compensation expense was $20,488 and $53,188 for the three and nine months ended September 30, 2022, respectively, and $20,662 and $26,120 for the three and nine months ended September 30, 2021, respectively. Stock based compensation expense is included in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss as shown in the following table: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Cost of revenues $ 11 $ 6 $ 27 $ 8 Research and development 8,030 3,533 17,435 5,749 Sales and marketing 786 408 1,729 548 General and administrative 11,661 16,715 33,997 19,815 Total $ 20,488 $ 20,662 $ 53,188 $ 26,120 Nominal amounts of stock based compensation expense is capitalized into capitalized software for the three and nine months ended September 30, 2022 and 2021.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
COMMITMENTS AND CONTINGENCIES	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal Proceedings — From time to time, the Company may become involved in various legal proceedings in the ordinary course of its business and may be subject to third-party infringement claims. The outcome of any such claims or proceedings, regardless of the merits, is inherently uncertain. The Company is not currently party to any material legal proceedings Sales and use and value-added tax (“VAT”) — The Company determined that it was required to pay sales and use and VAT taxes in various jurisdictions. The Company is in the process of filing voluntary disclosure agreements with certain jurisdictions and remitting the estimated taxes. If these jurisdictions determine that additional amounts are necessary, the Company will be required to pay accordingly. Related Parties — The Company has determined that there were no transactions with related parties as of or during the three and nine months ended September 30, 2022 and 2021.

ACCRUED EXPENSES AND OTHER CURR

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	9 Months Ended
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	Sep. 30, 2022
Other Liabilities Disclosure [Abstract]
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES Accrued expenses and other current liabilities consisted of the following: September 30, December 31, 2021 Obligations under current leases $ 4,636 $ 3,336 Employee-related costs 3,699 2,075 Sales and VAT tax accrual 2,159 2,319 Marketing related accruals 918 1,078 Other 5,766 4,125 Total $ 17,178 $ 12,933

EMPLOYEE BENEFIT PLAN

EMPLOYEE BENEFIT PLAN	9 Months Ended
EMPLOYEE BENEFIT PLAN	Sep. 30, 2022
Postemployment Benefits [Abstract]
EMPLOYEE BENEFIT PLAN	EMPLOYEE BENEFIT PLANThe Company sponsors a profit sharing plan with a 401(k) feature, the Duolingo Retirement Plan, (the “Plan”) for eligible employees. The current Plan, effective January 1, 2021, provides for Company safe harbor matching contributions of 100% of the first 4% of the employees’ elective deferrals and 50% of the next 2%, with vesting starting upon the first day of employment. The Company also has the option to make discretionary matching or profit sharing contributions. The Company made safe harbor matching contributions of approximately $1,097 and $3,139 for the three and nine months ended September 30, 2022, respectively, and $877 and $2,360 for the three and nine months ended September 30, 2021, respectively. The Company did not make any discretionary matching or profit sharing contributions during the three and nine months ended September 30, 2022 or 2021.

LOSS PER SHARE

LOSS PER SHARE	9 Months Ended
LOSS PER SHARE	Sep. 30, 2022
Earnings Per Share [Abstract]
LOSS PER SHARE	LOSS PER SHARE Basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities. Prior to the automatic conversion of all of its convertible preferred stock outstanding into Class B common stock upon the IPO, the Company considered all series of its convertible preferred stock to be participating securities. Under the two-class method, the net loss attributable to common stockholders is not allocated to the convertible preferred stock as the holders of the convertible preferred stock do not have a contractual obligation to share in the Company’s losses. Basic net loss per share attributable to common stockholders is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase. The diluted net loss per share attributable to common stockholders is calculated by giving effect to all potential dilutive common stock equivalents outstanding for the period. Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except per share data) 2022 2021 2022 2021 Numerator: Net loss attributable to Class A and Class B common shareholders $ (18,445) $ (28,970) $ (45,644) $ (42,618) Denominator: Weighted-average shares in computing net loss per share attributable to Class A and Class B common stockholders, basic and diluted 39,753 29,531 39,210 18,600 Basic loss per common share $ (0.46) $ (0.98) $ (1.16) $ (2.29) Diluted loss per common share $ (0.46) $ (0.98) $ (1.16) $ (2.29) The rights, including the liquidation and dividend rights, of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to 20 votes per share. Each share of Class B common stock is convertible into a share of Class A common stock voluntarily at any time by the holder, and automatically upon certain events. The Class A common stock has no conversion rights. As the liquidation and dividend rights are identical for Class A and Class B common stock, the undistributed earnings are allocated on a proportional basis and the resulting net loss per share attributable to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. Since the Company was in a net loss position for the three and nine months ended September 30, 2022 and 2021, there is no difference between the number of shares used to calculate basic and diluted loss per share. The potential shares of common stock that were excluded from the computation of diluted net loss per share attributable to common stockholders for the period presented because including them would have been antidilutive are as follows: Three and Nine Months Ended September 30, (in thousands) 2022 2021 Founder awards where performance has been met 180 90 Stock options 3,671 4,830 Vested, not released, RSUs 3 — Total 3,854 4,920 Founder awards of 1,620, where the performance criteria has not been satisfied, are excluded from the above table because the stock-price hurdles for those awards had not been met as of September 30, 2022.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
SUBSEQUENT EVENTS	Sep. 30, 2022
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS The Company has evaluated subsequent events through the filing of this Form 10-Q, and determined that there have been no events that have occurred that would require adjustments to our disclosures in the consolidated financial statements except for the following: On October 3, 2022, the Company completed the acquisition of the assets of Gunner Made LLC (“Gunner”), a wholly owned entity of PNG Holdings LLC, a design and animation studio based in Detroit, Michigan. The acquisition of Gunner added fifteen new designers, illustrators, and animators to Duolingo’s existing design teams. The total consideration was $4.5 million, of which $4 million was paid in cash upon closing and $0.5 million will be paid after one year of continued service of certain Gunner employees. The Company is currently in the process of completing the preliminary purchase price allocation, which will be included in the Company’s Annual Report on Form 10-K for the year ending December 31, 2022.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Sep. 30, 2022
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation—The Unaudited Condensed Consolidated Financial Statements include the accounts of the Company and subsidiaries over which the Company has control. All intercompany transactions and balances have been eliminated.
Basis of Presentation and Accounting Principles	Basis of Presentation —The accompanying Unaudited Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) from the Company’s accounting records and reflect the consolidated financial position and results of operations for the three and nine months ended September 30, 2022 and 2021. Unless otherwise specified, all dollar amounts are referred to in thousands. Accounting Principles —The Unaudited Condensed Consolidated Financial Statements and accompanying notes are prepared in accordance with GAAP.
Use of Estimates	Use of Estimates— The preparation of Unaudited Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Unaudited Condensed Consolidated Financial Statements and accompanying notes. Significant estimates and assumptions reflected in the Unaudited Condensed Consolidated Financial Statements include, but are not limited to, useful lives of property and equipment, valuation of deferred tax assets and liabilities, stock-based compensation, common stock valuation, operating lease right-of-use assets and liabilities, capitalization of internally developed software and associated useful lives and contingent liabilities. Actual results may differ materially from such estimates. Management believes that the estimates, and judgments upon which they rely, are reasonable based upon information available to them at the time that these estimates and judgments are made. To the extent that there are material differences between these estimates and actual results, the Company’s Unaudited Condensed Consolidated Financial Statements will be affected.
Cash and Cash Equivalents	Cash and Cash Equivalents—Cash consists primarily of cash on hand and bank deposits. Cash equivalents consist primarily of money market accounts with maturities of three months or less at the date of acquisition and are stated at cost, which approximates fair value. The Company maintains cash deposits with financial institutions that may exceed federally insured limits at times.The Money market funds are considered Level 1 financial assets. Level 1 financial assets use inputs that are the unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.
Advertising Costs	Advertising Costs — Advertising costs were approximately $12,807 and $12,013 for the three months ended September 30, 2022 and 2021, respectively, and $34,354 and $31,764 for the nine months ended September 30, 2022 and 2021, respectively, and are included within Sales and marketing in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss.
Income Taxes	Income Taxes— The Company’s provision for income taxes is computed by using an estimate of the annual effective tax rate, adjusted for discrete items taken into account in the relevant period, if any. Each quarter, the annual effective income tax rate is recomputed and if there are material changes in the estimate, a cumulative adjustment is made.
Concentration of Credit Risk	Concentration of Credit Risk —The Company’s concentration of credit risk relates to financial institutions holding the Company’s cash and cash equivalents and platforms with significant accounts receivable balances and revenue transactions.
Impairment of long-lived assets	Impairment of long-lived assets— The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If the sum of the estimated undiscounted future cash flows expected to result from the use and eventual disposition of an asset is less than the carrying amount of the asset, an impairment loss is recognized. Measurement of an impairment loss is based on the fair value of the asset.
Recently Issued Pronouncements Not Yet Adopted	Recently Issued Pronouncements Not Yet Adopted There are no recently issued accounting pronouncements that the Company has not yet adopted that they believe are applicable or would have a material impact on the financial statements of the Company.
Revenue Recognition	REVENUE The Company has three predominant sources of revenues; time-based subscriptions, in-app advertising placement by third parties, and the Duolingo English Test. Revenue is recognized upon transfer of control of promised products or services to users in an amount that reflects the consideration the Company expects to receive in exchange for those services. The Company does not enter into contracts with a customer that contain multiple promises that result in multiple performance obligations. Revenue is recorded net of taxes assessed by a government authority that are both imposed on and concurrent with specific revenue transactions between us and our users. Revenue from time-based subscriptions includes a stand-ready obligation to provide hosting services that are consumed by the customer over the subscription period. Users can purchase Duolingo monthly or they can purchase a six-month or year-long subscription and pay for the subscription at the time of purchase. Under the year-long subscription, users can also purchase a single plan or a family plan. The family plan includes up to six users on one subscription. Such payments are initially recorded to deferred revenue. The user has the ability to download limited content offline. However, as there is a significant level of integration and interdependency with the online functionality, the Company considers the service to be a single performance obligation for the online and offline content. The Company enters into arrangements with advertising networks to monetize the in-app advertising inventory. Revenue from in-app advertising placement is recognized at a point in time when the advertisement is placed and is based upon the amount received. Duolingo English Test revenue is generally recognized once the tests have gone through the proctoring process and a certification decision has been made. This process usually takes less than 48 hours after the test has been completed and uploaded. Customers have 21 days from the date of purchase to take the exam or their purchase will expire and revenue will be recognized. Virtually all customers complete their exams prior to expiration. Sometimes organizations may purchase tests in bulk via coupons with a one year expiration date. The Company will defer revenue from all tests that haven’t been proctored nor expired. The Company’s users have the option to purchase consumable in-app virtual goods. The Company recognizes revenue over the period in which the user consumes the virtual good, which is generally within a month. Principal Agent Considerations —The Company makes its application available to be downloaded through third-party digital distribution service providers. Users who purchase subscriptions also pay through the respective app stores. The Company evaluates the purchases via third-party payment processors to determine whether its revenues should be reported gross or net of fees retained by the payment processor. The Company is the principal in the transaction with the end user as a result of controlling, hosting, and integrating the delivery of the virtual items to the end user. The Company records revenue gross as a principal and records fees paid to third-party payment processors as Cost of revenues. Contract Balances —Deferred revenue mostly consists of payments we receive in advance of revenue recognition, and is mostly related to time-based subscriptions, which will be recognized into revenue over the course of the upcoming year (recognized over 12 months or less). Additionally, the Duolingo English Test has deferred revenue related to tests that have been purchased, but will not be recognized until the tests have been proctored. Disaggregation of Revenue In accordance with Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers , the Company disaggregates revenue from contracts with customers into source of revenue, which most closely depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	Sep. 30, 2022
Accounting Policies [Abstract]
Schedule of Cash and Cash Equivalents	The following table shows the breakout between cash and money market funds. September 30, December 31, Cash $ 87,248 $ 44,165 Money market funds 512,719 509,757 Total $ 599,967 $ 553,922

REVENUE (Tables)

REVENUE (Tables)	9 Months Ended
REVENUE (Tables)	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Schedule of Revenue Sources and Streams	Information regarding source of revenues: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Over time $ 72,172 $ 46,030 $ 195,376 $ 129,587 Point in time 23,893 17,565 70,295 48,171 Total revenue $ 96,065 $ 63,595 $ 265,671 $ 177,758 Information regarding revenue by stream: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Revenues: Subscription $ 72,172 $ 46,030 $ 195,376 $ 129,587 Advertising 10,619 9,029 33,585 27,360 Duolingo English Test 8,192 6,695 24,308 16,563 Other (1) 5,082 1,841 12,402 4,248 Total revenues $ 96,065 $ 63,595 $ 265,671 $ 177,758 ________________ (1) Other revenue is mainly comprised of in-app purchases of virtual goods.
Schedule of Deferred Revenues	Changes in deferred revenues were as follows: Nine Months Ended September 30, 2022 2021 Beginning balance—January 1 $ 98,267 $ 54,792 Amount from beginning balance recognized into revenue (89,387) (51,254) Recognition of deferred revenue (122,527) (83,088) Deferral of revenue 248,591 160,010 Ending balance—September 30 $ 134,944 $ 80,460

PROPERTY and EQUIPMENT, net (Ta

PROPERTY and EQUIPMENT, net (Tables)	9 Months Ended
PROPERTY and EQUIPMENT, net (Tables)	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property and equipment consists of the following as of September 30, 2022 and December 31, 2021: September 30, December 31, 2021 Leasehold improvements $ 15,602 $ 10,258 Furniture, fixtures and equipment 4,942 3,053 Total property and equipment 20,544 13,311 Less: accumulated depreciation (7,353) (5,100) Total property and equipment, net $ 13,191 $ 8,211 Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2022 2021 2022 2021 Research and development $ 627 $ 99 $ 1,224 $ 133 Sales and marketing 78 13 156 17 General and administrative 295 433 873 1,335 Total $ 1,000 $ 545 $ 2,253 $ 1,485

CAPITALIZED SOFTWARE, net (Tabl

CAPITALIZED SOFTWARE, net (Tables)	9 Months Ended
CAPITALIZED SOFTWARE, net (Tables)	Sep. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Capitalized Software	Capitalized software consists of the following as of September 30, 2022 and December 31, 2021: September 30, December 31, 2021 Capitalized software $ 14,769 $ 11,144 Less: accumulated amortization (7,751) (6,578) Capitalized software, net $ 7,018 $ 4,566
Finite-lived Intangible Assets Amortization Expense	Amortization expense is included within the following financial statement line items within the Company’s Unaudited Condensed Consolidated Financial Statements. Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2022 2021 2022 2021 Cost of revenues $ 274 $ — $ 547 $ — Sales and marketing 208 188 626 484 Total $ 482 $ 188 $ 1,173 $ 484

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
STOCK-BASED COMPENSATION (Tables)	Sep. 30, 2022
Equity [Abstract]
Share-based Payment Arrangement, Option, Activity	A summary of stock option and RSU activity under the Plans was as follows: Number of Weighted- Weighted- average remaining contractual life (years) Aggregate intrinsic value Options outstanding at January 1, 2022 6,255 $ 12.53 6.92 $ 585,339 Granted — — Exercised (1,585) 8.34 Repurchased — — Forfeited and expired (95) 16.82 Options outstanding at September 30, 2022 4,575 $ 13.89 6.49 $ 372,206 Options exercisable at September 30, 2022 3,671 $ 12.78 6.22 $ 302,468
Share-based Payment Arrangement, RSU, Activity	Restricted stock units Weighted- Outstanding at January 1, 2022 730 $ 77.09 Granted 1,415 92.10 Released (229) 78.44 Forfeited (62) 80.08 Outstanding at September 30, 2022 1,854 $ 88.28
Share-based Payment Arrangement, Payment Award	Tranche Company Stock Price Hurdle Number of RSUs Eligible to Vest 1 $ 127.50 90 2 $ 153.00 90 3 $ 178.50 90 4 $ 204.00 180 5 $ 255.00 180 6 $ 306.00 180 7 $ 357.00 180 8 $ 408.00 180 9 $ 612.00 270 10 $ 816.00 360
Share-based Payment Arrangement, Expensed, Amount	Stock based compensation expense is included in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss as shown in the following table: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Cost of revenues $ 11 $ 6 $ 27 $ 8 Research and development 8,030 3,533 17,435 5,749 Sales and marketing 786 408 1,729 548 General and administrative 11,661 16,715 33,997 19,815 Total $ 20,488 $ 20,662 $ 53,188 $ 26,120

ACCRUED EXPENSES AND OTHER CU_2

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)	9 Months Ended
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)	Sep. 30, 2022
Other Liabilities Disclosure [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following: September 30, December 31, 2021 Obligations under current leases $ 4,636 $ 3,336 Employee-related costs 3,699 2,075 Sales and VAT tax accrual 2,159 2,319 Marketing related accruals 918 1,078 Other 5,766 4,125 Total $ 17,178 $ 12,933

LOSS PER SHARE (Tables)

LOSS PER SHARE (Tables)	9 Months Ended
LOSS PER SHARE (Tables)	Sep. 30, 2022
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The diluted net loss per share attributable to common stockholders is calculated by giving effect to all potential dilutive common stock equivalents outstanding for the period. Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except per share data) 2022 2021 2022 2021 Numerator: Net loss attributable to Class A and Class B common shareholders $ (18,445) $ (28,970) $ (45,644) $ (42,618) Denominator: Weighted-average shares in computing net loss per share attributable to Class A and Class B common stockholders, basic and diluted 39,753 29,531 39,210 18,600 Basic loss per common share $ (0.46) $ (0.98) $ (1.16) $ (2.29) Diluted loss per common share $ (0.46) $ (0.98) $ (1.16) $ (2.29)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The potential shares of common stock that were excluded from the computation of diluted net loss per share attributable to common stockholders for the period presented because including them would have been antidilutive are as follows: Three and Nine Months Ended September 30, (in thousands) 2022 2021 Founder awards where performance has been met 180 90 Stock options 3,671 4,830 Vested, not released, RSUs 3 — Total 3,854 4,920

DESCRIPTION OF THE BUSINESS A_2

DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION (Details) $ / shares in Units, $ in Thousands		9 Months Ended
	Jul. 30, 2021 USD ($) $ / shares shares	Sep. 30, 2022 USD ($) language	Sep. 30, 2021 USD ($)
Business And Organization [Line Items]
Issuance of common stock in connection with the initial public offering, net of underwriting discounts and issuance costs \| $	$ 455,532	$ 0	$ 426,191
Number of languages, more than \| language		40
Common Class A \| IPO
Business And Organization [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	5,872,000
Sale of stock, price per share (in usd per share) \| $ / shares	$ 102
Common Class A \| IPO \| Stockholders
Business And Organization [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	1,406,000
Common Class A \| IPO \| Duolingo
Business And Organization [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	4,466,000
Common Class A \| Over-Allotment Option
Business And Organization [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	766,000

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 599,967	$ 553,922
Cash
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	87,248	44,165
Money market funds
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 512,719	$ 509,757

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Concentration Risk [Line Items]
Advertising costs	$ 12,807	$ 12,013	$ 34,354	$ 31,764
Accounts Receivable \| Customer Concentration Risk \| Apple
Concentration Risk [Line Items]
Concentration risk, percentage			54.60%		51.10%
Accounts Receivable \| Customer Concentration Risk \| Google
Concentration Risk [Line Items]
Concentration risk, percentage			26.60%		27.90%
Accounts Receivable \| Customer Concentration Risk \| Stripe
Concentration Risk [Line Items]
Concentration risk, percentage					10.10%
Revenue Benchmark \| Customer Concentration Risk \| Apple
Concentration Risk [Line Items]
Concentration risk, percentage	55.20%	51.60%	53.40%	51.20%
Revenue Benchmark \| Customer Concentration Risk \| Google
Concentration Risk [Line Items]
Concentration risk, percentage	27.70%	29.30%	28.40%	29%
Revenue Benchmark \| Customer Concentration Risk \| Stripe
Concentration Risk [Line Items]
Concentration risk, percentage		12.10%		11%

REVENUE - Narrative (Details)

REVENUE - Narrative (Details)	Sep. 30, 2022 sourceOfRevenue user
Disaggregation of Revenue [Line Items]
Number of sources of revenue \| sourceOfRevenue	3
Number of users \| user	6
Number of hours to make certification decision	48 hours
Number of days to take exam	21 days
Expiration period to take exams	1 year
Minimum
Disaggregation of Revenue [Line Items]
Subscription period	6 months
Maximum
Disaggregation of Revenue [Line Items]
Subscription period	1 year

REVENUE - Disaggregation of Rev

REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 96,065	$ 63,595	$ 265,671	$ 177,758
Over time
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	72,172	46,030	195,376	129,587
Over time \| Subscription
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	72,172	46,030	195,376	129,587
Over time \| Advertising
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	10,619	9,029	33,585	27,360
Over time \| Duolingo English Test
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	8,192	6,695	24,308	16,563
Over time \| Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	5,082	1,841	12,402	4,248
Point in time
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 23,893	$ 17,565	$ 70,295	$ 48,171

REVENUE - Deferred Revenue Roll

REVENUE - Deferred Revenue Rollforward (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Revenue from Contract with Customer, Liability [Roll Forward]
Beginning balance	$ 98,267	$ 54,792
Amount from beginning balance recognized into revenue	(89,387)	(51,254)
Recognition of deferred revenue	(122,527)	(83,088)
Deferral of revenue	248,591	160,010
Ending balance	$ 134,944	$ 80,460

PROPERTY and EQUIPMENT, net - S

PROPERTY and EQUIPMENT, net - Summary (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 20,544	$ 13,311
Less: accumulated depreciation	(7,353)	(5,100)
Total property and equipment, net	13,191	8,211
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	15,602	10,258
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 4,942	$ 3,053

PROPERTY and EQUIPMENT, net - N

PROPERTY and EQUIPMENT, net - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 1,000	$ 545	$ 2,253	$ 1,485

PROPERTY and EQUIPMENT, net -_2

PROPERTY and EQUIPMENT, net - Summary of Depreciation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Property, Plant and Equipment [Line Items]
Total	$ 1,000	$ 545	$ 2,253	$ 1,485
Research and development
Property, Plant and Equipment [Line Items]
Total	627	99	1,224	133
Sales and marketing
Property, Plant and Equipment [Line Items]
Total	78	13	156	17
General and administrative
Property, Plant and Equipment [Line Items]
Total	$ 295	$ 433	$ 873	$ 1,335

CAPITALIZED SOFTWARE, net - Cap

CAPITALIZED SOFTWARE, net - Capitalized Software (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Capitalized software	$ 14,769	$ 11,144
Less: accumulated amortization	(7,751)	(6,578)
Capitalized software, net	$ 7,018	$ 4,566

CAPITALIZED SOFTWARE, net - Nar

CAPITALIZED SOFTWARE, net - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of capitalized computer software	$ 482	$ 188	$ 1,173	$ 484

CAPITALIZED SOFTWARE, net - Sch

CAPITALIZED SOFTWARE, net - Schedule of Capitalized Software Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Finite-Lived Intangible Assets [Line Items]
Amortization of capitalized computer software	$ 482	$ 188	$ 1,173	$ 484
Cost of revenues
Finite-Lived Intangible Assets [Line Items]
Amortization of capitalized computer software	274	0	547	0
Sales and marketing
Finite-Lived Intangible Assets [Line Items]
Amortization of capitalized computer software	$ 208	$ 188	$ 626	$ 484

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Effective income tax rate	(0.30%)	(0.20%)	(0.50%)	(0.20%)
Foreign deferred tax asset					$ 418
Provision for income taxes	$ 53	$ 51	$ 222	$ 69
Pretax income (loss)	$ (18,392)	$ (28,919)	$ (45,422)	$ (42,549)

STOCK-BASED COMPENSATION - Narr

STOCK-BASED COMPENSATION - Narrative (Details) $ / shares in Units, shares in Thousands, $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 01, 2022 shares	Jun. 30, 2021 shares	Sep. 30, 2022 USD ($) day shares	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) tranche day $ / shares shares	Sep. 30, 2021 USD ($)	Jul. 26, 2021 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value, exercised					$ 129,725	$ 102,628
Unrecognized compensation cost, options			$ 6,955		6,955
Unrecognized compensation cost			$ 161,068		$ 161,068
Closing trading price, specified calendar \| day			60		60
Compensation expense			$ 20,488	$ 20,662	$ 53,188	$ 26,120
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, weighted-average period of recognition					2 years
Number of options available for grant (in shares) \| shares			8,409		8,409
Vested, not released, RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, weighted-average period of recognition					3 years
Unrecognized compensation expense, excluding options			$ 154,113		$ 154,113
Equity instruments other than options, grants in period (in shares) \| shares					1,415
Performance Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, excluding options			70,656		$ 70,656
Performance Based RSUs \| Share-Based Payment Arrangement, Founders
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in usd per share) \| $ / shares					$ 61.56
Performance Based RSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award service period					3 years 6 months 29 days
Performance Based RSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award service period					5 years 11 months 1 day
Performance Based RSUs \| Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense			7,572		$ 23,699
Performance Based RSUs \| Founders
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, excluding options			$ 110,817		$ 110,817
Equity instruments other than options, grants in period (in shares) \| shares		1,800
Settlement period after vesting		1 year
Award vesting percentage		25%
Number of tranches \| tranche					10
Award service period		10 years
Performance Based RSUs \| Founders \| Tranche One and Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of tranches \| tranche					2
2021 Plan \| Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares) \| shares	1,913						7,946
Share-based compensation, shares outstanding increase, maximum amount (in percent)	5%
Employee Stock Purchase Plan \| Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares) \| shares	166						1,119
2011 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					4 years
Share-based compensation, term of award					10 years

STOCK-BASED COMPENSATION - Stoc

STOCK-BASED COMPENSATION - Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares
Number of options
Options outstanding, beginning balance (in shares) \| shares	6,255
Granted (in shares) \| shares	0
Exercised (in shares) \| shares	(1,585)
Repurchased (in shares) \| shares	0
Forfeited and expired (in shares) \| shares	(95)
Options outstanding, ending balance (in shares) \| shares	4,575	6,255
Number of options exercisable (in shares) \| shares	3,671
Weighted- average exercise price
Outstanding, beginning balance (in usd per share) \| $ / shares	$ 12.53
Granted (in usd per share) \| $ / shares	0
Exercised (in usd per share) \| $ / shares	8.34
Repurchased (in usd per share) \| $ / shares	0
Forfeited and expired (in usd per share) \| $ / shares	16.82
Outstanding, ending balance (in usd per share) \| $ / shares	13.89	$ 12.53
Weighted average exercise price, options exercisable (in usd per share) \| $ / shares	$ 12.78
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term (in years), outstanding	6 years 5 months 26 days	6 years 11 months 1 day
Weighted average remaining contractual term (in years), exercisable	6 years 2 months 19 days
Aggregate intrinsic value, outstanding \| $	$ 372,206	$ 585,339
Aggregate intrinsic value, exercisable \| $	$ 302,468

STOCK-BASED COMPENSATION - Sche

STOCK-BASED COMPENSATION - Schedule of Restricted Stock Unit Activity (Details) - Vested, not released, RSUs - $ / shares shares in Thousands	9 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Restricted stock units
Beginning balance (in shares)	1,854	730
Granted (in shares)	1,415
Released (in shares)	(229)
Forfeited (in shares)	(62)
Ending balance (in shares)	1,854
Weighted- average grant date fair value per share
Beginning balance (in usd per share)	$ 77.09
Granted (in usd per share)	92.10
Released (in usd per share)	78.44
Forfeited (in usd per share)	80.08
Ending balance (in usd per share)	$ 88.28

STOCK-BASED COMPENSATION - Sc_2

STOCK-BASED COMPENSATION - Schedule of Payment Award (Details) - Vested, not released, RSUs shares in Thousands	Sep. 30, 2022 $ / shares shares
1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 127.50
Number of RSUs Eligible to Vest (in shares) \| shares	90
2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 153
Number of RSUs Eligible to Vest (in shares) \| shares	90
3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 178.50
Number of RSUs Eligible to Vest (in shares) \| shares	90
4
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 204
Number of RSUs Eligible to Vest (in shares) \| shares	180
5
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 255
Number of RSUs Eligible to Vest (in shares) \| shares	180
6
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 306
Number of RSUs Eligible to Vest (in shares) \| shares	180
7
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 357
Number of RSUs Eligible to Vest (in shares) \| shares	180
8
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 408
Number of RSUs Eligible to Vest (in shares) \| shares	180
9
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 612
Number of RSUs Eligible to Vest (in shares) \| shares	270
10
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 816
Number of RSUs Eligible to Vest (in shares) \| shares	360

STOCK-BASED COMPENSATION - Sc_3

STOCK-BASED COMPENSATION - Schedule of Income Statement Location for Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 20,488	$ 20,662	$ 53,188	$ 26,120
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	11	6	27	8
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	8,030	3,533	17,435	5,749
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	786	408	1,729	548
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 11,661	$ 16,715	$ 33,997	$ 19,815

ACCRUED EXPENSES AND OTHER CU_3

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Other Liabilities Disclosure [Abstract]
Obligations under current leases	$ 4,636	$ 3,336
Employee-related costs	3,699	2,075
Sales and VAT tax accrual	2,159	2,319
Marketing related accruals	918	1,078
Other	5,766	4,125
Total	$ 17,178	$ 12,933

EMPLOYEE BENEFIT PLAN (Details)

EMPLOYEE BENEFIT PLAN (Details) - USD ($)	3 Months Ended		9 Months Ended
EMPLOYEE BENEFIT PLAN (Details) - USD ($)	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, contributions by employer	$ 1,097,000	$ 877,000	$ 3,139,000	$ 2,360,000
Defined contribution plan, employer discretionary contribution amount	$ 0	$ 0	$ 0	$ 0
First 4% of Employee Elective Deferral
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match			100%
Employer matching contribution, percent of employees' gross pay			4%
Next 2% of Employee Elective Deferral
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match			50%
Employer matching contribution, percent of employees' gross pay			2%

LOSS PER SHARE - Schedule of Ea

LOSS PER SHARE - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Net loss	$ (18,445)	$ (28,970)	$ (45,644)	$ (42,618)
Denominator:
Weighted-average shares in computing net loss per share attributable to Class A and Class B common stockholders, basic (in shares)	39,753	29,531	39,210	18,600
Weighted-average shares in computing net loss per share attributable to Class A and Class B common stockholders, diluted (in shares)	39,753	29,531	39,210	18,600
Basic loss per common share (in usd per share)	$ (0.46)	$ (0.98)	$ (1.16)	$ (2.29)
Diluted loss per common share (in usd per share)	$ (0.46)	$ (0.98)	$ (1.16)	$ (2.29)

LOSS PER SHARE - Narrative (Det

LOSS PER SHARE - Narrative (Details) shares in Thousands	9 Months Ended
LOSS PER SHARE - Narrative (Details) shares in Thousands	Sep. 30, 2022 votePerShare numberOfVotesPerShare shares
Performance Based RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Founder awards where performance not met \| shares	1,620
Common Class A
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Voting rights, per share \| votePerShare	1
Common Class B
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Voting rights, per share \| numberOfVotesPerShare	20

LOSS PER SHARE - Schedule of An

LOSS PER SHARE - Schedule of Antidilutive Securities (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	3,854,000	4,920,000	3,854,000	4,920,000
Founder awards where performance has been met
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	180,000	90,000	180,000	90,000
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	3,671,000	4,830,000	3,671,000	4,830,000
Vested, not released, RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	3,000	0	3,000	0

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - Subsequent Event - Gunner Made LLC $ in Millions	Oct. 03, 2022 USD ($) employee
Subsequent Event [Line Items]
Number of design team members \| employee	15
Asset acquisition, consideration transferred	$ 4.5
Cash paid in asset acquisition	4
Asset acquisition, amount held back until one year of continued service	$ 0.5