PubMatic (PUBM) 10-Q 10 Nov 21 2021 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2021	Oct. 31, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-39748
Entity Registrant Name	PUBMATIC, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-5863224
Entity Address, Address Line One	3 Lagoon Drive
Entity Address, Address Line Two	Suite 180
Entity Address, City or Town	Redwood City
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94065
Title of 12(b) Security	Class A common stock, $0.0001 par value per share
Trading Symbol	PUBM
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
Amendment Flag	false
Entity Central Index Key	0001422930
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		27,545,541
Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		23,760,497

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current Assets
Cash and cash equivalents	$ 89,376	$ 81,188
Marketable securities	47,355	19,793
Accounts receivable - net	228,387	219,511
Prepaid expenses and other current assets	12,974	6,622
Total Current Assets	378,092	327,114
Property, equipment and software - net	51,927	30,044
Goodwill	6,250	6,250
Deferred income tax asset	495	762
Other assets, non-current	2,081	7,076
TOTAL ASSETS	438,845	371,246
Current Liabilities
Accounts payable	195,332	176,731
Accrued liabilities	17,661	14,844
Total Current Liabilities	212,993	191,575
Deferred tax liability	2,698	1,561
Other liabilities, non-current	2,317	2,683
TOTAL LIABILITIES	218,008	195,819
Commitments and contingencies (Note 6)
Stockholders' Equity
Preferred stock, $0.0001 par value per share, 10,000,000 shares authorized as of September 30, 2021 and December 31, 2020; No shares issued and outstanding as of September 30, 2021 and December 31, 2020	0	0
Common stock, par value $0.0001 per share; 1,000,000,000 Class A shares authorized as of September 30, 2021 and December 31, 2020; 27,436,489 and 6,801,368 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively; 1,000,000,000 Class B shares authorized as of September 30, 2021 and December 31, 2020; 23,443,849 and 42,186,774 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively.	6	6
Treasury stock, at cost - 3,140,437 and 3,139,295 shares as of September 30, 2021 and December 31, 2020, respectively.	(11,486)	(11,434)
Additional paid-in capital	161,261	144,163
Accumulated other comprehensive income	0	1
Retained earnings	71,056	42,691
Total Stockholders' Equity	220,837	175,427
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 438,845	$ 371,246

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Preferred stock par value (in usd per share)	$ 0.0001	$ 0.0001
Preferred stock shares authorized	10,000,000	10,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Treasury stock shares	3,140,437	3,139,295
Class A
Common stock par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock shares authorized	1,000,000,000	1,000,000,000
Common stock shares issued	27,436,489	6,801,368
Common stock shares outstanding	27,436,489	6,801,368
Class B
Common stock par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock shares authorized	1,000,000,000	1,000,000,000
Common stock shares issued	23,443,849	42,186,774
Common stock shares outstanding	23,443,849	42,186,774

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenue	$ 58,086	$ 37,797	$ 151,352	$ 92,506
Cost of revenue	16,020	10,491	41,408	29,736
Gross profit	42,066	27,306	109,944	62,770
Operating expenses:
Technology and development	4,139	3,390	11,738	9,280
Sales and marketing	15,004	10,911	41,790	30,142
General and administration	8,875	5,214	25,593	13,799
Total operating expenses	28,018	19,515	79,121	53,221
Operating income	14,048	7,791	30,823	9,549
Interest income	79	83	208	475
Other income (expense), net	198	(22)	29	(132)
Total other income (expense), net	277	61	237	343
Income before income taxes	14,325	7,852	31,060	9,892
Provision for income taxes	799	1,621	2,695	2,104
Net income	$ 13,526	$ 6,231	$ 28,365	$ 7,788
Net income per share attributable to common stockholders:
Basic (in usd per share)	$ 0.27	$ 0.12	$ 0.57	$ 0.10
Diluted (in usd per share)	$ 0.24	$ 0.10	$ 0.50	$ 0.09
Weighted-average shares used to compute net income per share attributable to common stockholders:
Basic (in shares)	50,559,636	10,335,359	49,754,449	10,178,598
Diluted (in shares)	56,498,891	15,876,890	56,575,867	14,072,248

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Other Comprehensive Income [Abstract]
Net income	$ 13,526	$ 6,231	$ 28,365	$ 7,788
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities, net of tax	0	(7)	(1)	(4)
Comprehensive income	$ 13,526	$ 6,224	$ 28,364	$ 7,784

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Convertible Preferred Stock	Redeemable Common Stock
Beginning balance (in shares) at Dec. 31, 2019							33,443,969	5,901,863
Beginning balance at Dec. 31, 2019							$ 61,216	$ 19,025
Ending balance (in shares) at Mar. 31, 2020							33,443,969	5,901,863
Ending balance at Mar. 31, 2020							$ 61,216	$ 19,025
Beginning balance (in shares) at Dec. 31, 2019		5,746,216
Beginning balance at Dec. 31, 2019	$ 13,295	$ 1	$ (11,431)	$ 8,641	$ 6	$ 16,078
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	503			503
Exercise of stock options (in shares)		58,452
Exercise of stock options	74			74
Other comprehensive income (loss)	20				20
Net income	904					904
Ending balance (in shares) at Mar. 31, 2020		5,804,668
Ending balance at Mar. 31, 2020	14,796	$ 1	(11,431)	9,218	26	16,982
Beginning balance (in shares) at Dec. 31, 2019							33,443,969	5,901,863
Beginning balance at Dec. 31, 2019							$ 61,216	$ 19,025
Ending balance (in shares) at Sep. 30, 2020							33,443,969	0
Ending balance at Sep. 30, 2020							$ 61,216	$ 0
Beginning balance (in shares) at Dec. 31, 2019		5,746,216
Beginning balance at Dec. 31, 2019	13,295	$ 1	(11,431)	8,641	6	16,078
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,788
Ending balance (in shares) at Sep. 30, 2020		11,727,535
Ending balance at Sep. 30, 2020	46,924	$ 2	(11,432)	34,486	2	23,866
Beginning balance (in shares) at Mar. 31, 2020							33,443,969	5,901,863
Beginning balance at Mar. 31, 2020							$ 61,216	$ 19,025
Ending balance (in shares) at Jun. 30, 2020							33,443,969	5,901,863
Ending balance at Jun. 30, 2020							$ 61,216	$ 19,025
Beginning balance (in shares) at Mar. 31, 2020		5,804,668
Beginning balance at Mar. 31, 2020	14,796	$ 1	(11,431)	9,218	26	16,982
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	505			505
Other comprehensive income (loss)	(17)				(17)
Net income	653					653
Ending balance (in shares) at Jun. 30, 2020		5,804,668
Ending balance at Jun. 30, 2020	15,937	$ 1	(11,431)	9,723	9	17,635
Increase (Decrease) in Temporary Equity [Roll Forward]
Reclassification of redeemable common stock (in shares)								(5,901,863)
Reclassification of redeemable common stock								$ (19,025)
Ending balance (in shares) at Sep. 30, 2020							33,443,969	0
Ending balance at Sep. 30, 2020							$ 61,216	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	1,451			1,451
Exercise of stock options (in shares)		21,584
Exercise of stock options	20			20
Repurchase of treasury stock, at cost (in shares)		(580)
Repurchase of treasury stock, at cost	(1)		(1)
Repayment of stockholders' notes receivable and accrued interest	4,268			4,268
Issuance of common stock related to RSU vesting (in shares)		5,901,863
Reclassifications of Temporary to Permanent Equity	19,025	$ 1		19,024
Other comprehensive income (loss)	(7)				(7)
Net income	6,231					6,231
Ending balance (in shares) at Sep. 30, 2020		11,727,535
Ending balance at Sep. 30, 2020	46,924	$ 2	(11,432)	34,486	2	23,866
Beginning balance (in shares) at Dec. 31, 2020							0	0
Beginning balance at Dec. 31, 2020							$ 0	$ 0
Ending balance (in shares) at Mar. 31, 2021							0	0
Ending balance at Mar. 31, 2021							$ 0	$ 0
Beginning balance (in shares) at Dec. 31, 2020		48,988,142
Beginning balance at Dec. 31, 2020	175,427	$ 6	(11,434)	144,163	1	42,691
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	3,318			3,318
Exercise of stock options (in shares)		278,412
Exercise of stock options	451			451
Repurchase of treasury stock, at cost (in shares)		(693)
Repurchase of treasury stock, at cost	(27)		(27)
Other comprehensive income (loss)	(1)				(1)
Net income	4,918					4,918
Ending balance (in shares) at Mar. 31, 2021		49,265,861
Ending balance at Mar. 31, 2021	184,086	$ 6	(11,461)	147,932	0	47,609
Beginning balance (in shares) at Dec. 31, 2020							0	0
Beginning balance at Dec. 31, 2020							$ 0	$ 0
Ending balance (in shares) at Sep. 30, 2021							0	0
Ending balance at Sep. 30, 2021							$ 0	$ 0
Beginning balance (in shares) at Dec. 31, 2020		48,988,142
Beginning balance at Dec. 31, 2020	$ 175,427	$ 6	(11,434)	144,163	1	42,691
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	1,694,511
Net income	$ 28,365
Ending balance (in shares) at Sep. 30, 2021		50,880,338
Ending balance at Sep. 30, 2021	220,837	$ 6	(11,486)	161,261	0	71,056
Beginning balance (in shares) at Mar. 31, 2021							0	0
Beginning balance at Mar. 31, 2021							$ 0	$ 0
Ending balance (in shares) at Jun. 30, 2021							0	0
Ending balance at Jun. 30, 2021							$ 0	$ 0
Beginning balance (in shares) at Mar. 31, 2021		49,265,861
Beginning balance at Mar. 31, 2021	184,086	$ 6	(11,461)	147,932	0	47,609
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	3,837			3,837
Exercise of stock options (in shares)		800,426
Exercise of stock options	1,627			1,627
Repurchase of treasury stock, at cost (in shares)		(449)
Repurchase of treasury stock, at cost	(25)		(25)
Issuance of common stock related to employee stock purchase plan (in shares)		155,015
Issuance of common stock related to employee stock purchase plan	2,635			2,635
Issuance of common stock related to RSU vesting (in shares)		21,973
Net income	9,921					9,921
Ending balance (in shares) at Jun. 30, 2021		50,242,826
Ending balance at Jun. 30, 2021	202,081	$ 6	(11,486)	156,031	0	57,530
Ending balance (in shares) at Sep. 30, 2021							0	0
Ending balance at Sep. 30, 2021							$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	3,981			3,981
Exercise of stock options (in shares)		615,673
Exercise of stock options	1,249			1,249
Issuance of common stock related to RSU vesting (in shares)		21,839
Net income	13,526					13,526
Ending balance (in shares) at Sep. 30, 2021		50,880,338
Ending balance at Sep. 30, 2021	$ 220,837	$ 6	$ (11,486)	$ 161,261	$ 0	$ 71,056

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Statement of Cash Flows [Abstract]
Net income	$ 28,365	$ 7,788
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	15,992	11,574
Stock-based compensation	10,508	2,439
Provision for doubtful accounts	0	319
Deferred income taxes	1,404	92
Accretion of discount on marketable securities	(46)	(135)
Other	(2)	32
Changes in operating assets and liabilities:
Accounts receivable	(8,876)	(23,190)
Prepaid expenses and other current assets	(6,620)	(996)
Accounts payable	16,648	18,289
Accrued expenses	3,195	465
Other liabilities, non-current	(366)	(971)
Net cash provided by operating activities	60,202	15,706
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(22,846)	(12,885)
Capitalized software development costs	(6,755)	(5,638)
Purchases of marketable securities	(53,118)	(22,313)
Proceeds from sales of marketable securities	0	2,295
Proceeds from maturities of marketable securities	25,600	26,750
Net cash used in investing activities	(57,119)	(11,791)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock for employee stock purchase plan	2,635	0
Proceeds from repayments of stockholders’ notes receivable	0	4,268
Proceeds from exercise of stock options	3,327	94
Payments for offering costs	(805)	(1,914)
Payments to acquire treasury stock	(52)	(1)
Net cash provided by financing activities	5,105	2,447
NET INCREASE IN CASH AND CASH EQUIVALENTS	8,188	6,362
CASH AND CASH EQUIVALENTS - Beginning of period	81,188	34,250
CASH AND CASH EQUIVALENTS - End of period	89,376	40,612
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Income taxes paid	4,445	415
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Stock-based compensation capitalized as internal use software costs	628	20
Property and equipment included in accounts payable and accrued expenses	2,712	1,624
Capitalized software costs included in accounts payable and accrued expenses	1,115	636
Deferred offering costs incurred during the period included in accounts payable and accrued expenses	$ 0	$ 22

Organization and Description of

Organization and Description of Business	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of BusinessPubMatic, Inc. and subsidiaries (“Company” or “PubMatic”) was founded in 2006. The Company has offices in California, New York, Europe, Asia, and Australia. The Company provides a specialized cloud infrastructure platform that enables real-time programmatic advertising transactions. The purpose-built technology and infrastructure provides superior outcomes for both publishers and advertisers leveraging an efficient design, machine learning, and data processing capabilities, with customer alignment and global omnichannel reach.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Fiscal Year The Company’s fiscal year ends on December 31, and its fiscal quarters end on March 31, June 30, September 30, and December 31. References to fiscal year 2021, for example, refer to the fiscal year ended December 31, 2021. Unaudited Interim Condensed Consolidated Financial Information The unaudited condensed consolidated financial statements include the accounts of PubMatic, Inc. and its wholly owned subsidiaries, and have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and following the requirements of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. These financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for the fair statement of the Company’s financial information. These interim results are not necessarily indicative of the results to be expected for the fiscal year ending December 31, 2021 or for any other interim period or for any other future year. The accompanying unaudited condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and the related notes contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020, as filed with the SEC on March 26, 2021 (the “Annual Report”). Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in accordance with GAAP. The accompanying condensed consolidated financial statements include the accounts of PubMatic, Inc. and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Initial Public Offering The Company’s registration statement on Form S-1 (the “IPO Registration Statement”) related to its initial public offering (“IPO”) was declared effective on December 8, 2020, and the Company’s Class A common stock began trading on the Nasdaq Global Market on December 9, 2020. On December 11, 2020, the Company completed its IPO, in which the Company sold 2,655,000 shares of Class A common stock at a price to the public of $20.00 per share. The Company received aggregate net proceeds of $45.0 million after deducting underwriting discounts, commissions and offering costs. In connection with the IPO, all of the shares of convertible preferred stock outstanding automatically converted into an aggregate of 33,443,969 shares of Class B common stock. Deferred offering costs consisted primarily of accounting, legal, and other fees related to the IPO. Prior to the IPO, all deferred offering costs were capitalized in prepaid expenses and other current assets in the condensed consolidated balance sheets. Upon consummation of the IPO, the $4.4 million of deferred offering costs were reclassified to stockholders’ equity and recorded against the proceeds from the offering. No offering costs were capitalized as of September 30, 2021. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities, and reported amounts of revenue and expenses. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates and assumptions. Due to the inherent uncertainty involved in making assumptions and estimates, events and changes in circumstances arising after September 30, 2021, including those resulting from the impacts of the COVID-19 pandemic, may result in actual outcomes that differ from those contemplated by the Company’s assumptions and estimates. Stock-Based Compensation The Company recognizes and measures compensation expense for all stock-based payment awards granted to employees, directors, and nonemployees, including stock options, restricted stock units (“RSUs”), and the employee stock purchase plan (the “ESPP”) based on the fair value of the awards on the date of grant. The fair value of stock options and shares of common stock to be issued under the ESPP is estimated using the Black Scholes option pricing model. The grant date fair value of RSUs is based on the closing market price of the Company’s Class A common stock on the date of grant. The Black Scholes option pricing model is impacted by the fair value of the Company’s common stock, as well as changes in assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, the expected common stock price volatility over the term of the stock options, the expected term of the stock options, risk-free interest rates, and the expected dividend yield. For additional information regarding stock-based compensation and the assumptions used for determining the fair value of stock options and ESPP awards, refer to Note 9 — “Stockholders’ Equity and Stock Option Plans.” Concentration of Revenue and Accounts Receivable The Company defines its revenue concentration based on revenue recognized from individual publishers. For the three months ended September 30, 2021 and 2020, one publisher represented 17% and 18%, respectively, and 18% and 21% for the nine months ended September 30, 2021 and 2020, respectively, of the Company’s revenue. As of September 30, 2021, three buyers accounted for 28%, 20% and 10%, respectively, of accounts receivable. As of December 31, 2020, four buyers accounted for 33%, 14%, 13% and 11%, respectively, of accounts receivable. Net Income Per Share Attributable to Common Stockholders Basic and diluted net income per share attributable to Class A and Class B common stock is computed in conformity with the two-class method required for participating securities. The Company considers the preferred stock as participating securities. Holders of participating securities do not have a contractual obligation to share in the Company’s losses. In accordance with the two-class method, earnings allocated to these participating securities and the related number of outstanding shares of the participating securities have been excluded from the computation of basic and diluted net income per share attributable to common stockholders. Distributed and undistributed earnings allocated to participating securities are subtracted from net income in determining net income attributable to common stockholders. Basic net income per share is computed by dividing net income attributable to common stockholders by the weighted-average number of shares of the Company’s Class A and Class B common stock outstanding. The diluted net income per share attributable to common stockholders is computed by giving effect to all dilutive securities. Diluted net income per share attributable to common stockholders is computed by dividing the resulting net income attributable to common stockholders by the weighted-average number of fully diluted common shares outstanding. During the periods when there is a net loss attributable to common stockholders, potentially dilutive common stock equivalents have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is anti-dilutive. Recently Adopted Accounting Pronouncements In December 2019, the Financial Accounting Standards Board (“FASB”) issued ASU 2019-12—Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to general principles in Topic 740 and clarifies and amends existing guidance for clarity and consistent application. Effective on January 1, 2021, the Company adopted this standard, which did not have a material impact on the condensed consolidated financial statements and related disclosures. Recent Accounting Pronouncements Not Yet Adopted Under the Jumpstart Our Business Startups Act (the “JOBS Act”), the Company meets the definition of an emerging growth company (“EGC”) and can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company elected to use this extended transition period under the JOBS Act until such time the Company is no longer considered to be an EGC. The Company expects to cease being an EGC as of December 31, 2021, becoming a large accelerated filer. The adoption dates discussed below reflect the updated transition period for complying with accounting standards not yet adopted. In February 2016, FASB issued ASU No. 2016-02, Leases , which requires an entity to recognize right-of-use assets and lease liabilities on its balance sheet and disclose key information about leasing arrangements. The guidance offers specific accounting guidance for a lessee, lessor, and sale and leaseback transactions. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. Leases will be classified as either finance or operating, with the classification affecting the pattern of expense recognition in the income statement. The guidance is effective for the Company for fiscal year 2021 and the adoption, including the impact and required disclosures will be included in its 2021 Form 10-K. The guidance requires a modified retrospective adoption. The Company expects that most of its operating lease commitments will be recognized as operating lease liabilities and right-of-use assets upon adoption of the new guidance. In June 2016, FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). This update changes the accounting for recognizing impairments of financial assets, such that credit losses for certain types of financial instruments will be estimated based on expected losses. The update also modifies the impairment models for available-for-sale debt securities and for purchased financial assets with credit deterioration since their origination. ASU 2016-13 is effective for the Company in fiscal year 2021 and the adoption, including the impact and required disclosures will be included in its 2021 Form 10-K. The Company does not expect the adoption of this guidance to have a material impact on the Company's consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other: Simplifying the Test for Goodwill Impairment (“ASU 2017-04”). ASU 2017-04 eliminates Step 2 from the goodwill impairment test which measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Under ASU 2017-04, an entity should perform its annual or interim goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount, and should recognize an impairment loss for the amount by which the carrying amount exceeds the reporting unit’s fair value, with the loss not exceeding the total amount of goodwill allocated to that reporting unit. ASU 2017-04 will be effective for the Company in fiscal year 2021 and will be included in its 2021 Form 10-K. At adoption, this update will require a prospective approach. The Company does not expect the adoption of this guidance to have a material impact on the Company's consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following table sets forth the fair value of the Company’s financial assets and liabilities measured on a recurring basis by level within the fair value hierarchy (in thousands): September 30, 2021 Level I Level II Level III Total Financial Assets Money market funds $ 65,128 $ — $ — $ 65,128 Certificates of deposit — 6,502 — 6,502 Cash equivalents 65,128 6,502 — 71,630 Commercial paper — 47,355 — 47,355 Marketable securities — 47,355 — 47,355 Total Financial Assets $ 65,128 $ 53,857 $ — $ 118,985 December 31, 2020 Level I Level II Level III Total Financial Assets Money market funds (1) $ 12,462 $ — $ — $ 12,462 Commercial paper (1) — 7,199 — 7,199 Cash equivalents 12,462 7,199 — 19,661 U.S. Treasury and government debt securities — 8,999 — 8,999 Commercial paper — 10,794 — 10,794 Marketable securities — 19,793 — 19,793 Total Financial Assets $ 12,462 $ 26,992 $ — $ 39,454 _______________ (1) The amounts were previously combined and presented as cash equivalents. Prior periods have been reclassified to conform with current period presentation. The Company’s financial assets consist of Level I and II assets. The Company had no Level III assets or liabilities for the periods presented. The Company classifies its cash equivalents and marketable securities within Level I or Level II because they are valued using either quoted market prices or inputs other than quoted prices which are directly or indirectly observable in the market, including readily-available pricing sources for the identical underlying security which may not be actively traded. The Company’s fixed income available-for-sale securities consist of high quality, investment grade securities from diverse issuers. The valuation techniques used to measure the fair value of the Company’s marketable securities were derived from non-binding market consensus prices that are corroborated by observable market data and quoted market prices for similar instruments.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Marketable Securities The following table summarizes the Company’s marketable securities by significant investment categories (in thousands): September 30, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Commercial paper $ 47,355 $ — $ — $ 47,355 Total $ 47,355 $ — $ — $ 47,355 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Commercial paper $ 10,794 $ — $ — $ 10,794 U.S. Treasury and government debt securities $ 8,998 $ 1 $ — $ 8,999 Total $ 19,792 $ 1 $ — $ 19,793 The remaining contractual maturity of all marketable securities was within one year as of September 30, 2021 and December 31, 2020. Realized gains and losses were not material for the three and nine months ended September 30, 2021 and 2020. As of September 30, 2021 and 2020, there were no securities that were in an unrealized loss position for more than twelve months. Property, Equipment and Software, Net Property, equipment and software, net consists of the following (in thousands): September 30, December 31, Internal-use software $ 31,674 $ 24,513 Network hardware, computer equipment and software 91,615 62,764 Leasehold improvements 2,098 1,249 Furniture and fixtures 620 621 Property, equipment and software, gross 126,007 89,147 Less: accumulated depreciation and amortization (74,080) (59,103) Total property, equipment and software, net $ 51,927 $ 30,044 Depreciation and amortization expense related to property, equipment, and software (excluding amortization of internal use software) was $4.4 million and $2.6 million for the three months ended September 30, 2021 and 2020, respectively, and $10.7 million and $7.2 million for the nine months ended September 30, 2021 and 2020, respectively. The Company capitalized $2.6 million and $1.6 million in software development costs during the three months ended September 30, 2021 and 2020, respectively, and $7.2 million and $5.1 million for the nine months ended September 30, 2021 and 2020, respectively. Amortization expense of internal use software was $1.9 million and $1.6 million during the three months ended September 30, 2021 and 2020, respectively, and $5.3 million and $4.4 million for the nine months ended September 30, 2021 and 2020, respectively. These costs are included within cost of revenue in the condensed consolidated statements of operations and comprehensive income. The Company did not recognize any impairment charges on its long-lived assets during the nine months ended September 30, 2021 and 2020, respectively. Accounts Payable Accounts payable consists of the following (in thousands): September 30, December 31, Payable to publishers $ 185,530 $ 168,673 Other 9,802 8,058 Total accounts payable $ 195,332 $ 176,731 Accrued Expenses Accrued expenses consist of the following (in thousands): September 30, December 31, Accrued compensation $ 13,205 $ 13,352 Accrued and other current liabilities 4,456 1,492 Total accrued expenses $ 17,661 $ 14,844

Loan and Security Agreement

Loan and Security Agreement	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Loan and Security Agreement	Loan and Security Agreement In June 2021, the Company amended and restated its loan and security agreement (the "Loan Agreement") with Silicon Valley Bank ("SVB".) The Loan Agreement provides a senior secured revolving credit facility of up to $25.0 million or 80% of eligible accounts receivable less certain reserves, minus the aggregate principal amount of all outstanding advances. Interest accrues on advances under the revolving line of credit at a variable rate equal to the greater of prime rate or 3.25%. As of September 30, 2021, the applicable interest rate under the revolving line of credit was 3.25%. An unused revolver fee in the amount of 0.40% per annum of the average unused portion of the revolver line is charged and is payable quarterly in arrears in any quarter where the average closing outstanding balance is less than $5.0 million. The maturity date of the revolving line of credit is June 6, 2024. As of September 30, 2021 there were no outstanding advances under the revolving line of credit. The Company’s obligations under the line of credit and the letters of credit (described in Note 6) with SVB are secured by substantially all of its assets excluding its intellectual property. The Loan Agreement contains affirmative covenants including financial covenants that, among other things, require the Company to maintain an adjusted quick ratio of no less than 1.0 to 1.0. The adjusted quick ratio is defined as the ratio of unrestricted cash and cash equivalents at SVB, plus billed accounts receivable to total accounts payable plus all SVB loans outstanding and outstanding letters of credit. The Loan Agreement also restricts the Company from paying dividends to stockholders without prior consent from SVB. The Company was in compliance with the financial covenants as of September 30, 2021.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases and Other Contractual Obligations The Company has commitments for future payments related to office facilities leases and other contractual obligations. The Company leases its office facilities under operating lease agreements that expire over varying time periods through the year ending December 31, 2023. Certain of these lease agreements have free or escalating rent payment provisions or fund certain leasehold improvements, which the Company accounts as lease incentives. The Company recognizes rent expense under such agreements on a straight-line basis over the lease term, with any lease incentive amortized as a reduction of rent expense over the lease term. The Company also has other contractual obligations expiring over varying time periods through the year ending December 31, 2024. Other contractual obligations primarily relate to minimum contractual payments due to data center providers. Future annual minimum commitments as of September 30, 2021, are as follows (in thousands): Leases Other Contractual Obligations 2021 (for remaining 3 months) $ 488 $ 2,261 2022 1,017 9,255 2023 106 7,234 2024 — 3,877 Total future minimum commitments, net $ 1,611 $ 22,627 Rent expense, net of sublease income, incurred under operating leases was $0.5 million and $0.6 million for three months ended September 30, 2021 and 2020, respectively, and $1.6 million and $1.9 million for the nine months ended September 30, 2021 and 2020, respectively. Rent expense was offset by sublease income of $0.1 million for the three months ended September 30, 2020 and $0.4 million for the nine months ended September 30, 2020. No rent expense was offset by sublease income for the nine months ended September 30, 2021. Letters of Credit As of September 30, 2021 and December 31, 2020, the Company had an irrevocable letter of credit outstanding related to non-cancelable facilities leases in the amounts of $0.7 million, with annual automatic renewal and final expiration date in June 2022. Legal Matters From time to time, the Company has become involved in claims and other legal matters arising in the normal course of business. The Company investigates these claims as they arise and accrues for contingencies when the Company believes that a loss is probable and that the Company can reasonably estimate the amount of any such loss. The Company has made an assessment of the probability of incurring any such losses and whether or not those losses are estimable and although claims are inherently unpredictable the Company concluded that these losses are not material to the Company’s business, financial position, results of operations, or cash flows. To the extent there is a reasonable possibility that a loss exceeding amounts already recognized may be incurred, and the amount of such additional loss would be material, the Company will either disclose the estimated additional loss or state that such an estimate cannot be made. Indemnification In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnification. The Company’s exposure under these agreements is unknown because it involves future claims that may be made against the Company but have not yet been made. To date, the Company has not paid any material claims or been required to defend any actions related to its indemnification obligations. However, the Company may record charges in the future as a result of these indemnification obligations. In addition, the Company has indemnification agreements with certain of its directors and executive officers that require it, among other things, to indemnify them against certain liabilities that may arise due to their status or service as directors or officers of the Company. The terms of such obligations may vary.

Convertible Preferred Stock

Convertible Preferred Stock	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Convertible Preferred Stock	Convertible Preferred Stock Upon completion of the IPO in December 11, 2020, all shares of convertible preferred stock outstanding, totaling 33,443,969 shares, were automatically converted into an equivalent number of shares of Class B common stock on a one-to-one basis and their carrying value of $61.2 million was reclassified into stockholders’ equity. As of September 30, 2021, there were no shares of convertible preferred stock issued and outstanding. In connection with the IPO, the Company’s restated certificate of incorporation became effective, which authorized the issuance of 10,000,000 shares of undesignated preferred stock with a par value of $0.0001 with rights and preferences, including voting rights, designated from time to time by the Company’s board of directors.

Stockholders_ Notes Receivable

Stockholders’ Notes Receivable and Redeemable Common Stock	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Stockholders’ Notes Receivable, Redeemable Common Stock and Stock Option Plans	Stockholders’ Notes Receivable and Redeemable Common Stock In August 2018, the Company loaned its Chief Executive Officer and Chief Growth Officer a total of $4.0 million under secured nonrecourse promissory notes (the “Notes”). The Notes bore interest at a rate of 2.42% per annum compounded annually and had a maturity date of August 30, 2021, with interest and principal due at maturity. The Notes were secured by pledges of 1.6 million shares of outstanding common stock of the Company owned by the two officers (the “Pledged Shares”). The Notes could be prepaid in cash at any time without penalty. At maturity and in certain events of default, the Notes could, at the option of the two officers, be repaid in cash or surrender and cancellation of the Pledged Shares at fair market value. If the Pledged Shares were insufficient to repay the entire amount due under the Notes, then the value of the Pledged Shares would be deemed to be the full amount due under the Notes. As the Company’s only recourse on the Notes and associated interest was the Pledged Shares, the Notes were accounted for as nonrecourse and recorded to stockholders’ equity as of September 30, 2020. This was accounted for as though the Company repurchased the Pledged Shares and in exchange issued the Notes and granted 1.6 million fully vested stock options with an exercise price equal to the face value of Notes plus interest. No principal or interest payments were paid during the three months ended September 30, 2020. During the quarter ended September 30, 2020, all principal and interest due under the notes were prepaid. In connection with the Notes, the Company provided the officers with a right to sell to the Company outstanding shares of common stock upon settlement of the Notes (the “Put Option”). The officers could only exercise the Put Option upon repayment of the Notes using the Pledged Shares or upon the prepayment of the Notes using proceeds from the officers’ sale or disposal of the Pledged Shares at a price less than the face value of the Notes. The Put Option allowed the officers to require the Company to repurchase any or all common stock held or beneficially owned to offset their tax liabilities resulting from the settlement of the Notes via one of the above methods. As the exercisability of the Put Option and therefore redemption of the common stock was outside the control of the Company, all common stock held or beneficially owned by the officers required temporary equity classification. The Company therefore classified $19.0 million of common stock outside of stockholders’ equity as of September 30, 2020, which represented the fair value of the shares held or beneficially owned on the transaction date. The Company did not adjust the carrying value of the redeemable common stock during the three months ended September 30, 2020 since a redemption event was not probable. The Put Option expired unexercised upon the repayment of the Notes and during the Company’s quarter ended September 30, 2020, the $19.0 million of redeemable common stock was reclassified back to common stock. Common Stock In connection with the IPO in December 2020, the Company’s restated certificate of incorporation became effective, which authorized 1,000,000,000 shares of Class A common stock, $0.0001 par value per share, and 1,000,000,000 shares of Class B common stock, $0.0001 par value per share. Class A and Class B common stock are referred to as common stock throughout the notes to the condensed consolidated financial statements, unless otherwise noted. Equity Incentive Plans Upon completion of the IPO, the Company adopted the 2020 Equity Incentive Plan (“2020 Plan”), pursuant to which the Company may grant stock options, restricted stock awards, stock appreciation rights, restricted stock units (“RSUs”), deferred stock units (“DSUs”) performance awards, and stock bonus awards. As of September 30, 2021, the Company has reserved 6,414,228 shares of Class A common stock for the issuance of awards under the 2020 Plan. These available shares will increase automatically on January 1 for each of the first ten calendar years during the term of the 2020 Plan by the number of shares equal to the lesser of five percent (5%) of the aggregate number of outstanding shares of all classes of the Company’s common stock outstanding as of the immediately preceding December 31, or a number as may be determined by the Company’s board of directors or compensation committee. To the extent outstanding awards under the 2017 Plan and the 2006 Plan are forfeited, lapse unexercised, or would otherwise have been returned to the share reserve under the Prior Plans, the shares of Class B common stock subject to such awards instead will be available for future issuance as Class A common stock under the 2020 Plan. No new awards were issued under the 2006 Plan or 2017 Plan after the effective date of the 2020 Plan. Stock Options A summary of stock option activity under the Company’s equity incentive plan and related information is as follows: Stock Options Number of Shares Underlying Outstanding Options Weighted-Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding — December 31, 2020 8,459,969 $ 2.53 6.83 $ 215,144 Options granted 660,466 36.74 Options exercised (1,694,511) 1.96 Options canceled/expired (27,094) 7.96 Outstanding — September 30, 2021 7,398,830 $ 5.69 7.01 $ 159,659 Vested — September 30, 2021 4,822,778 $ 3.12 6.13 $ 113,146 As of September 30, 2021, unrecognized stock-based compensation of $19.0 million related to unvested stock options will be recognized on a straight-line basis over a weighted average period of 2.91 years. Restricted Stock Units A summary of RSU activity under the Company’s equity incentive plan and related information is as follows: RSUs Number of Shares Weighted-Average Grant Date Fair Value per Share Unvested — December 31, 2020 — $ — Granted 507,406 35.45 Vested (43,812) 37.92 Canceled/Forfeited (11,281) 32.70 Unvested — September 30, 2021 452,313 $ 35.28 As of September 30, 2021, unrecognized stock-based compensation of $14.7 million related to unvested RSUs will be recognized on a straight-line basis over a weighted average period of 3.43 years. 2020 Employee Stock Purchase Plan In November 2020, the Company’s board of directors adopted, and its stockholders approved, the 2020 Employee Stock Purchase Plan (“ESPP”), which became effective in connection with the IPO. A total of 500,000 shares of the Company’s Class A common stock were initially reserved for issuance under the ESPP. The aggregate number of shares reserved for issuance under the ESPP will increase automatically on January 1st of each of the first ten calendar years during the term of the ESPP by the number of shares equal to the lesser of (a) 1% of the total outstanding shares of all classes of the Company’s common stock as of the immediately preceding December 31 and (b) such number of shares of common stock as determined by the Company’s board of directors. The aggregate number of shares issued over the term of the ESPP may not exceed 7,500,000 shares of Class A common stock. As of September 30, 2021, the Company has reserved 834,866 shares of its common stock for issuance under the ESPP. Under the ESPP, Class A common stock will be purchased for the accounts of employees participating in the ESPP on each purchase date at a price per share equal to 85% of the lesser of: (a) the fair market value on the offering date or (b) the fair market value on the purchase date. The ESPP provides for, at maximum, 27 month offering periods and each offering period may consist of one or more six-month purchase periods, beginning December 9, 2020 through May 31, 2022 with the purchase date on the last day of each purchase period. As of September 30, 2021, $1.5 million has been withheld on behalf of employees for a future purchase under the ESPP due to the timing of payroll deductions and is included in accrued and other current liabilities. For the nine months ended September 30, 2021, 155,015 shares of our Class A common stock have been purchased under the ESPP. As of September 30, 2021, unrecognized stock-based compensation expense related to the ESPP was $2.4 million, which is expected to be recognized over a weighted-average period of 0.67 years. Stock-Based Compensation The total stock-based compensation recognized in the condensed consolidated statements of operations and comprehensive income is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Cost of revenue $ 233 $ 10 $ 605 $ 30 Technology and development 586 222 1,646 377 Sales and marketing 1,388 358 3,839 721 General and administrative 1,507 854 4,418 1,311 Total stock-based compensation 3,714 1,444 10,508 2,439 Tax benefit from stock-based compensation (521) (206) (1,401) (293) Total stock-based compensation, net of tax effect $ 3,193 $ 1,238 $ 9,107 $ 2,146

Stockholders_ Equity and Stock

Stockholders’ Equity and Stock Option Plans	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Stockholders’ Notes Receivable, Redeemable Common Stock and Stock Option Plans	Stockholders’ Notes Receivable and Redeemable Common Stock In August 2018, the Company loaned its Chief Executive Officer and Chief Growth Officer a total of $4.0 million under secured nonrecourse promissory notes (the “Notes”). The Notes bore interest at a rate of 2.42% per annum compounded annually and had a maturity date of August 30, 2021, with interest and principal due at maturity. The Notes were secured by pledges of 1.6 million shares of outstanding common stock of the Company owned by the two officers (the “Pledged Shares”). The Notes could be prepaid in cash at any time without penalty. At maturity and in certain events of default, the Notes could, at the option of the two officers, be repaid in cash or surrender and cancellation of the Pledged Shares at fair market value. If the Pledged Shares were insufficient to repay the entire amount due under the Notes, then the value of the Pledged Shares would be deemed to be the full amount due under the Notes. As the Company’s only recourse on the Notes and associated interest was the Pledged Shares, the Notes were accounted for as nonrecourse and recorded to stockholders’ equity as of September 30, 2020. This was accounted for as though the Company repurchased the Pledged Shares and in exchange issued the Notes and granted 1.6 million fully vested stock options with an exercise price equal to the face value of Notes plus interest. No principal or interest payments were paid during the three months ended September 30, 2020. During the quarter ended September 30, 2020, all principal and interest due under the notes were prepaid. In connection with the Notes, the Company provided the officers with a right to sell to the Company outstanding shares of common stock upon settlement of the Notes (the “Put Option”). The officers could only exercise the Put Option upon repayment of the Notes using the Pledged Shares or upon the prepayment of the Notes using proceeds from the officers’ sale or disposal of the Pledged Shares at a price less than the face value of the Notes. The Put Option allowed the officers to require the Company to repurchase any or all common stock held or beneficially owned to offset their tax liabilities resulting from the settlement of the Notes via one of the above methods. As the exercisability of the Put Option and therefore redemption of the common stock was outside the control of the Company, all common stock held or beneficially owned by the officers required temporary equity classification. The Company therefore classified $19.0 million of common stock outside of stockholders’ equity as of September 30, 2020, which represented the fair value of the shares held or beneficially owned on the transaction date. The Company did not adjust the carrying value of the redeemable common stock during the three months ended September 30, 2020 since a redemption event was not probable. The Put Option expired unexercised upon the repayment of the Notes and during the Company’s quarter ended September 30, 2020, the $19.0 million of redeemable common stock was reclassified back to common stock. Common Stock In connection with the IPO in December 2020, the Company’s restated certificate of incorporation became effective, which authorized 1,000,000,000 shares of Class A common stock, $0.0001 par value per share, and 1,000,000,000 shares of Class B common stock, $0.0001 par value per share. Class A and Class B common stock are referred to as common stock throughout the notes to the condensed consolidated financial statements, unless otherwise noted. Equity Incentive Plans Upon completion of the IPO, the Company adopted the 2020 Equity Incentive Plan (“2020 Plan”), pursuant to which the Company may grant stock options, restricted stock awards, stock appreciation rights, restricted stock units (“RSUs”), deferred stock units (“DSUs”) performance awards, and stock bonus awards. As of September 30, 2021, the Company has reserved 6,414,228 shares of Class A common stock for the issuance of awards under the 2020 Plan. These available shares will increase automatically on January 1 for each of the first ten calendar years during the term of the 2020 Plan by the number of shares equal to the lesser of five percent (5%) of the aggregate number of outstanding shares of all classes of the Company’s common stock outstanding as of the immediately preceding December 31, or a number as may be determined by the Company’s board of directors or compensation committee. To the extent outstanding awards under the 2017 Plan and the 2006 Plan are forfeited, lapse unexercised, or would otherwise have been returned to the share reserve under the Prior Plans, the shares of Class B common stock subject to such awards instead will be available for future issuance as Class A common stock under the 2020 Plan. No new awards were issued under the 2006 Plan or 2017 Plan after the effective date of the 2020 Plan. Stock Options A summary of stock option activity under the Company’s equity incentive plan and related information is as follows: Stock Options Number of Shares Underlying Outstanding Options Weighted-Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding — December 31, 2020 8,459,969 $ 2.53 6.83 $ 215,144 Options granted 660,466 36.74 Options exercised (1,694,511) 1.96 Options canceled/expired (27,094) 7.96 Outstanding — September 30, 2021 7,398,830 $ 5.69 7.01 $ 159,659 Vested — September 30, 2021 4,822,778 $ 3.12 6.13 $ 113,146 As of September 30, 2021, unrecognized stock-based compensation of $19.0 million related to unvested stock options will be recognized on a straight-line basis over a weighted average period of 2.91 years. Restricted Stock Units A summary of RSU activity under the Company’s equity incentive plan and related information is as follows: RSUs Number of Shares Weighted-Average Grant Date Fair Value per Share Unvested — December 31, 2020 — $ — Granted 507,406 35.45 Vested (43,812) 37.92 Canceled/Forfeited (11,281) 32.70 Unvested — September 30, 2021 452,313 $ 35.28 As of September 30, 2021, unrecognized stock-based compensation of $14.7 million related to unvested RSUs will be recognized on a straight-line basis over a weighted average period of 3.43 years. 2020 Employee Stock Purchase Plan In November 2020, the Company’s board of directors adopted, and its stockholders approved, the 2020 Employee Stock Purchase Plan (“ESPP”), which became effective in connection with the IPO. A total of 500,000 shares of the Company’s Class A common stock were initially reserved for issuance under the ESPP. The aggregate number of shares reserved for issuance under the ESPP will increase automatically on January 1st of each of the first ten calendar years during the term of the ESPP by the number of shares equal to the lesser of (a) 1% of the total outstanding shares of all classes of the Company’s common stock as of the immediately preceding December 31 and (b) such number of shares of common stock as determined by the Company’s board of directors. The aggregate number of shares issued over the term of the ESPP may not exceed 7,500,000 shares of Class A common stock. As of September 30, 2021, the Company has reserved 834,866 shares of its common stock for issuance under the ESPP. Under the ESPP, Class A common stock will be purchased for the accounts of employees participating in the ESPP on each purchase date at a price per share equal to 85% of the lesser of: (a) the fair market value on the offering date or (b) the fair market value on the purchase date. The ESPP provides for, at maximum, 27 month offering periods and each offering period may consist of one or more six-month purchase periods, beginning December 9, 2020 through May 31, 2022 with the purchase date on the last day of each purchase period. As of September 30, 2021, $1.5 million has been withheld on behalf of employees for a future purchase under the ESPP due to the timing of payroll deductions and is included in accrued and other current liabilities. For the nine months ended September 30, 2021, 155,015 shares of our Class A common stock have been purchased under the ESPP. As of September 30, 2021, unrecognized stock-based compensation expense related to the ESPP was $2.4 million, which is expected to be recognized over a weighted-average period of 0.67 years. Stock-Based Compensation The total stock-based compensation recognized in the condensed consolidated statements of operations and comprehensive income is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Cost of revenue $ 233 $ 10 $ 605 $ 30 Technology and development 586 222 1,646 377 Sales and marketing 1,388 358 3,839 721 General and administrative 1,507 854 4,418 1,311 Total stock-based compensation 3,714 1,444 10,508 2,439 Tax benefit from stock-based compensation (521) (206) (1,401) (293) Total stock-based compensation, net of tax effect $ 3,193 $ 1,238 $ 9,107 $ 2,146

Net Income Per Share Attributab

Net Income Per Share Attributable to Common Stockholders	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Income Per Share Attributable to Common Stockholders	Net Income Per Share Attributable to Common Stockholders The following table sets forth the computation of the Company’s basic and diluted net income per share (in thousands, except share and per share data): Three Months Ended September 30, 2021 2020 Class A Class B Class A Class B (in thousands, except share and per share data) Numerator: Net income $ 7,294 $ 6,232 $ — $ 6,231 Less: Undistributed earnings allocated to participating securities — — — (5,035) Reallocation of net income attributable to common stockholders (1,229) 1,229 — — Net income attributable to common stockholders – basic $ 6,065 $ 7,461 $ — $ 1,196 Denominator: Weighted average common shares outstanding – basic 22,669,223 27,890,413 — 10,335,359 Net income per share attributable to common stockholders – basic: $ 0.27 $ 0.27 $ — $ 0.12 Numerator: Net income attributable to common stockholders - diluted $ 5,445 $ 8,081 $ — $ 1,630 Denominator: Weighted average shares outstanding – basic 22,669,223 27,890,413 — 10,335,359 Options to purchase common stock — 5,864,634 — 5,541,531 Restricted stock 11,553 — — — Employee stock purchase plan shares 63,068 — — — Weighted average shares outstanding – diluted 22,743,844 33,755,047 — 15,876,890 Net income per share attributable to common stockholders – diluted $ 0.24 $ 0.24 $ — $ 0.10 The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net income per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: Three Months Ended September 30, 2021 2020 Class A Class B Class A Class B Options to purchase common stock 892,639 — — — Common stock issuable upon conversion of convertible preferred stock — — — 33,443,969 Total excludable from net income per share attributable to common stockholders – diluted 892,639 — — 33,443,969 Nine months ended September 30, 2021 2020 Class A Class B Class A Class B (in thousands, except share and per share data) Numerator: Net income $ 15,295 $ 13,070 $ — $ 7,788 Less: Undistributed earnings allocated to participating securities — — — (6,788) Reallocation of net income attributable to common stockholders (7,265) 7,265 — — Net income attributable to common stockholders – basic $ 8,030 $ 20,335 $ — $ 1,000 Denominator: Weighted average common shares outstanding – basic 14,087,401 35,667,048 — 10,178,598 Net income per share attributable to common stockholders – basic: $ 0.57 $ 0.57 $ — $ 0.10 Numerator: Net income attributable to common stockholders - diluted $ 7,146 $ 21,219 $ — $ 1,269 Denominator: Weighted average shares outstanding – basic 14,087,401 35,667,048 — 10,178,598 Options to purchase common stock 85,726 6,653,755 — 3,893,650 Restricted stock 23,222 — — — Employee stock purchase plan shares 58,715 — — — Weighted average shares outstanding – diluted 14,255,064 42,320,803 — 14,072,248 Net income per share attributable to common stockholders – diluted $ 0.50 $ 0.50 $ — $ 0.09 The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net income per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: Nine months ended September 30, 2021 2020 Class A Class B Class A Class B Options to purchase common stock 668,294 — — 1,128,642 Common stock issuable upon conversion of convertible preferred stock — — — 33,443,969 Total excludable from net income per share attributable to common stockholders – diluted 668,294 — — 34,572,611

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company computes its provision for income taxes by applying the estimated annual effective tax rate to pretax income and adjusts the provision for discrete tax items recorded in the period. The Company recorded a provision for income taxes of $0.8 million and $1.6 million for the three months ended September 30, 2021 and 2020, respectively, and a provision for income taxes of $2.7 million and $2.1 million for the nine months ended September 30, 2021 and 2020, respectively. The effective income tax rate was 9% and 21% for the nine months ended September 30, 2021 and 2020, respectively. The Company’s effective tax rate for the first nine months of 2021 was lower compared to the statutory tax rate primarily due to higher tax benefits from share-based compensation and tax benefits for federal and state research credits, partially offset by nondeductible stock-based compensation, Section 162(m) limitation on compensation expense to covered employees and a higher tax rate in certain foreign countries where the Company operates. Realization of the Company’s deferred tax assets is dependent primarily on the generation of future taxable income. In considering the need for a valuation allowance, the Company considers its historical, as well as future projected, taxable income along with other objectively verifiable evidence. Objectively verifiable evidence includes the Company’s realization of tax attributes, assessment of tax credits, and utilization of net operating loss carryforwards during the year.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Segment Information	Segment Information The following table represents total revenue by geographic area based on the publisher’s billing address (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 United States $ 36,451 $ 24,412 $ 93,935 $ 60,962 EMEA 15,552 8,925 41,306 20,454 APAC 4,909 3,777 13,245 9,396 Rest of the world 1,174 683 2,866 1,694 Total $ 58,086 $ 37,797 $ 151,352 $ 92,506 The Company’s long-lived assets, net by geographic area are summarized as follows (in thousands): September 30, December 31, 2020 United States $ 43,255 $ 24,580 Rest of the world 8,672 5,464 Total $ 51,927 $ 30,044

401(k) Plan

401(k) Plan	9 Months Ended
	Sep. 30, 2021
Retirement Benefits [Abstract]
401(k) Plan	401(k) PlanThe Company has a 401(k) Savings Plan (the “401(k) Plan”) that qualifies as a deferred salary arrangement under Section 401(k) of the Internal Revenue Code. Under the 401(k) Plan, participating employees may elect to contribute up to 100% of their eligible compensation, subject to certain limitations. The 401(k) Plan provides for a discretionary employer matching contribution. The Company made no matching contribution to the 401(k) Plan for the nine months ended September 30, 2021 and 2020, respectively.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events In October 2021, the Company entered into a new agreement to sublease approximately 34,229 square feet of office space located in Redwood City, California. The Company will use the space to support its general and administrative functions, sales and marketing, technology and development, engineering and customer support. Pursuant to the sublease agreement, as amended, the lease term will commence on December 1, 2021 and will terminate on March 31, 2028. The annual lease payments during the first year are approximately $3.4 million, escalating 3.0% annually thereafter. Rent expense will be recorded on a straight-line basis over the sublease term. The Company has provided an irrevocable letter of credit in the amount of approximately $3.5 million, pursuant to the terms of the sublease.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in accordance with GAAP. The accompanying condensed consolidated financial statements include the accounts of PubMatic, Inc. and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities, and reported amounts of revenue and expenses. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates and assumptions. Due to the inherent uncertainty involved in making assumptions and estimates, events and changes in circumstances arising after September 30, 2021, including those resulting from the impacts of the COVID-19 pandemic, may result in actual outcomes that differ from those contemplated by the Company’s assumptions and estimates.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes and measures compensation expense for all stock-based payment awards granted to employees, directors, and nonemployees, including stock options, restricted stock units (“RSUs”), and the employee stock purchase plan (the “ESPP”) based on the fair value of the awards on the date of grant. The fair value of stock options and shares of common stock to be issued under the ESPP is estimated using the Black Scholes option pricing model. The grant date fair value of RSUs is based on the closing market price of the Company’s Class A common stock on the date of grant. The Black Scholes option pricing model is impacted by the fair value of the Company’s common stock, as well as changes in assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, the expected common stock price volatility over the term of the stock options, the expected term of the stock options, risk-free interest rates, and the expected dividend yield. For additional information regarding stock-based compensation and the assumptions used for determining the fair value of stock options and ESPP awards, refer to Note 9 — “Stockholders’ Equity and Stock Option Plans.”
Net Income Per Share Attributable to Common Stockholders	Net Income Per Share Attributable to Common Stockholders Basic and diluted net income per share attributable to Class A and Class B common stock is computed in conformity with the two-class method required for participating securities. The Company considers the preferred stock as participating securities. Holders of participating securities do not have a contractual obligation to share in the Company’s losses. In accordance with the two-class method, earnings allocated to these participating securities and the related number of outstanding shares of the participating securities have been excluded from the computation of basic and diluted net income per share attributable to common stockholders. Distributed and undistributed earnings allocated to participating securities are subtracted from net income in determining net income attributable to common stockholders. Basic net income per share is computed by dividing net income attributable to common stockholders by the weighted-average number of shares of the Company’s Class A and Class B common stock outstanding. The diluted net income per share attributable to common stockholders is computed by giving effect to all dilutive securities. Diluted net income per share attributable to common stockholders is computed by dividing the resulting net income attributable to common stockholders by the weighted-average number of fully diluted common
Recently Adopted Accounting Pronouncements And Not Yet Adopted	Recently Adopted Accounting Pronouncements In December 2019, the Financial Accounting Standards Board (“FASB”) issued ASU 2019-12—Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to general principles in Topic 740 and clarifies and amends existing guidance for clarity and consistent application. Effective on January 1, 2021, the Company adopted this standard, which did not have a material impact on the condensed consolidated financial statements and related disclosures. Recent Accounting Pronouncements Not Yet Adopted Under the Jumpstart Our Business Startups Act (the “JOBS Act”), the Company meets the definition of an emerging growth company (“EGC”) and can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company elected to use this extended transition period under the JOBS Act until such time the Company is no longer considered to be an EGC. The Company expects to cease being an EGC as of December 31, 2021, becoming a large accelerated filer. The adoption dates discussed below reflect the updated transition period for complying with accounting standards not yet adopted. In February 2016, FASB issued ASU No. 2016-02, Leases , which requires an entity to recognize right-of-use assets and lease liabilities on its balance sheet and disclose key information about leasing arrangements. The guidance offers specific accounting guidance for a lessee, lessor, and sale and leaseback transactions. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. Leases will be classified as either finance or operating, with the classification affecting the pattern of expense recognition in the income statement. The guidance is effective for the Company for fiscal year 2021 and the adoption, including the impact and required disclosures will be included in its 2021 Form 10-K. The guidance requires a modified retrospective adoption. The Company expects that most of its operating lease commitments will be recognized as operating lease liabilities and right-of-use assets upon adoption of the new guidance. In June 2016, FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). This update changes the accounting for recognizing impairments of financial assets, such that credit losses for certain types of financial instruments will be estimated based on expected losses. The update also modifies the impairment models for available-for-sale debt securities and for purchased financial assets with credit deterioration since their origination. ASU 2016-13 is effective for the Company in fiscal year 2021 and the adoption, including the impact and required disclosures will be included in its 2021 Form 10-K. The Company does not expect the adoption of this guidance to have a material impact on the Company's consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other: Simplifying the Test for Goodwill Impairment (“ASU 2017-04”). ASU 2017-04 eliminates Step 2 from the goodwill impairment test which measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Under ASU 2017-04, an entity should perform its annual or interim goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount, and should recognize an impairment loss for the amount by which the carrying amount exceeds the reporting unit’s fair value, with the loss not exceeding the total amount of goodwill allocated to that reporting unit. ASU 2017-04 will be effective for the Company in fiscal year 2021 and will be included in its 2021 Form 10-K. At adoption, this update will require a prospective approach. The Company does not expect the adoption of this guidance to have a material impact on the Company's consolidated financial statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table sets forth the fair value of the Company’s financial assets and liabilities measured on a recurring basis by level within the fair value hierarchy (in thousands): September 30, 2021 Level I Level II Level III Total Financial Assets Money market funds $ 65,128 $ — $ — $ 65,128 Certificates of deposit — 6,502 — 6,502 Cash equivalents 65,128 6,502 — 71,630 Commercial paper — 47,355 — 47,355 Marketable securities — 47,355 — 47,355 Total Financial Assets $ 65,128 $ 53,857 $ — $ 118,985 December 31, 2020 Level I Level II Level III Total Financial Assets Money market funds (1) $ 12,462 $ — $ — $ 12,462 Commercial paper (1) — 7,199 — 7,199 Cash equivalents 12,462 7,199 — 19,661 U.S. Treasury and government debt securities — 8,999 — 8,999 Commercial paper — 10,794 — 10,794 Marketable securities — 19,793 — 19,793 Total Financial Assets $ 12,462 $ 26,992 $ — $ 39,454 _______________ (1) The amounts were previously combined and presented as cash equivalents. Prior periods have been reclassified to conform with current period presentation.

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Debt Securities, Available-for-sale	The following table summarizes the Company’s marketable securities by significant investment categories (in thousands): September 30, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Commercial paper $ 47,355 $ — $ — $ 47,355 Total $ 47,355 $ — $ — $ 47,355 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Loss Fair Value Commercial paper $ 10,794 $ — $ — $ 10,794 U.S. Treasury and government debt securities $ 8,998 $ 1 $ — $ 8,999 Total $ 19,792 $ 1 $ — $ 19,793
Property, Plant and Equipment	Property, equipment and software, net consists of the following (in thousands): September 30, December 31, Internal-use software $ 31,674 $ 24,513 Network hardware, computer equipment and software 91,615 62,764 Leasehold improvements 2,098 1,249 Furniture and fixtures 620 621 Property, equipment and software, gross 126,007 89,147 Less: accumulated depreciation and amortization (74,080) (59,103) Total property, equipment and software, net $ 51,927 $ 30,044
Schedule of Accounts Payable and Accrued Liabilities	Accounts payable consists of the following (in thousands): September 30, December 31, Payable to publishers $ 185,530 $ 168,673 Other 9,802 8,058 Total accounts payable $ 195,332 $ 176,731
Schedule of Accrued Liabilities	Accrued expenses consist of the following (in thousands): September 30, December 31, Accrued compensation $ 13,205 $ 13,352 Accrued and other current liabilities 4,456 1,492 Total accrued expenses $ 17,661 $ 14,844

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Contractual Obligation, Fiscal Year Maturity	Future annual minimum commitments as of September 30, 2021, are as follows (in thousands): Leases Other Contractual Obligations 2021 (for remaining 3 months) $ 488 $ 2,261 2022 1,017 9,255 2023 106 7,234 2024 — 3,877 Total future minimum commitments, net $ 1,611 $ 22,627

Stockholders_ Equity and Stoc_2

Stockholders’ Equity and Stock Option Plans (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award	Stock Options Number of Shares Underlying Outstanding Options Weighted-Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding — December 31, 2020 8,459,969 $ 2.53 6.83 $ 215,144 Options granted 660,466 36.74 Options exercised (1,694,511) 1.96 Options canceled/expired (27,094) 7.96 Outstanding — September 30, 2021 7,398,830 $ 5.69 7.01 $ 159,659 Vested — September 30, 2021 4,822,778 $ 3.12 6.13 $ 113,146 RSUs Number of Shares Weighted-Average Grant Date Fair Value per Share Unvested — December 31, 2020 — $ — Granted 507,406 35.45 Vested (43,812) 37.92 Canceled/Forfeited (11,281) 32.70 Unvested — September 30, 2021 452,313 $ 35.28
Share-based Payment Arrangement, Expensed and Capitalized, Amount	The total stock-based compensation recognized in the condensed consolidated statements of operations and comprehensive income is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Cost of revenue $ 233 $ 10 $ 605 $ 30 Technology and development 586 222 1,646 377 Sales and marketing 1,388 358 3,839 721 General and administrative 1,507 854 4,418 1,311 Total stock-based compensation 3,714 1,444 10,508 2,439 Tax benefit from stock-based compensation (521) (206) (1,401) (293) Total stock-based compensation, net of tax effect $ 3,193 $ 1,238 $ 9,107 $ 2,146

Net Income Per Share Attribut_2

Net Income Per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Earnings per Share, Basic, by Common Class, Including Two Class Method	The following table sets forth the computation of the Company’s basic and diluted net income per share (in thousands, except share and per share data): Three Months Ended September 30, 2021 2020 Class A Class B Class A Class B (in thousands, except share and per share data) Numerator: Net income $ 7,294 $ 6,232 $ — $ 6,231 Less: Undistributed earnings allocated to participating securities — — — (5,035) Reallocation of net income attributable to common stockholders (1,229) 1,229 — — Net income attributable to common stockholders – basic $ 6,065 $ 7,461 $ — $ 1,196 Denominator: Weighted average common shares outstanding – basic 22,669,223 27,890,413 — 10,335,359 Net income per share attributable to common stockholders – basic: $ 0.27 $ 0.27 $ — $ 0.12 Numerator: Net income attributable to common stockholders - diluted $ 5,445 $ 8,081 $ — $ 1,630 Denominator: Weighted average shares outstanding – basic 22,669,223 27,890,413 — 10,335,359 Options to purchase common stock — 5,864,634 — 5,541,531 Restricted stock 11,553 — — — Employee stock purchase plan shares 63,068 — — — Weighted average shares outstanding – diluted 22,743,844 33,755,047 — 15,876,890 Net income per share attributable to common stockholders – diluted $ 0.24 $ 0.24 $ — $ 0.10 Nine months ended September 30, 2021 2020 Class A Class B Class A Class B (in thousands, except share and per share data) Numerator: Net income $ 15,295 $ 13,070 $ — $ 7,788 Less: Undistributed earnings allocated to participating securities — — — (6,788) Reallocation of net income attributable to common stockholders (7,265) 7,265 — — Net income attributable to common stockholders – basic $ 8,030 $ 20,335 $ — $ 1,000 Denominator: Weighted average common shares outstanding – basic 14,087,401 35,667,048 — 10,178,598 Net income per share attributable to common stockholders – basic: $ 0.57 $ 0.57 $ — $ 0.10 Numerator: Net income attributable to common stockholders - diluted $ 7,146 $ 21,219 $ — $ 1,269 Denominator: Weighted average shares outstanding – basic 14,087,401 35,667,048 — 10,178,598 Options to purchase common stock 85,726 6,653,755 — 3,893,650 Restricted stock 23,222 — — — Employee stock purchase plan shares 58,715 — — — Weighted average shares outstanding – diluted 14,255,064 42,320,803 — 14,072,248 Net income per share attributable to common stockholders – diluted $ 0.50 $ 0.50 $ — $ 0.09
Schedule of Earnings per Share, Diluted, by Common Class, Including Two Class Method	The following table sets forth the computation of the Company’s basic and diluted net income per share (in thousands, except share and per share data): Three Months Ended September 30, 2021 2020 Class A Class B Class A Class B (in thousands, except share and per share data) Numerator: Net income $ 7,294 $ 6,232 $ — $ 6,231 Less: Undistributed earnings allocated to participating securities — — — (5,035) Reallocation of net income attributable to common stockholders (1,229) 1,229 — — Net income attributable to common stockholders – basic $ 6,065 $ 7,461 $ — $ 1,196 Denominator: Weighted average common shares outstanding – basic 22,669,223 27,890,413 — 10,335,359 Net income per share attributable to common stockholders – basic: $ 0.27 $ 0.27 $ — $ 0.12 Numerator: Net income attributable to common stockholders - diluted $ 5,445 $ 8,081 $ — $ 1,630 Denominator: Weighted average shares outstanding – basic 22,669,223 27,890,413 — 10,335,359 Options to purchase common stock — 5,864,634 — 5,541,531 Restricted stock 11,553 — — — Employee stock purchase plan shares 63,068 — — — Weighted average shares outstanding – diluted 22,743,844 33,755,047 — 15,876,890 Net income per share attributable to common stockholders – diluted $ 0.24 $ 0.24 $ — $ 0.10 Nine months ended September 30, 2021 2020 Class A Class B Class A Class B (in thousands, except share and per share data) Numerator: Net income $ 15,295 $ 13,070 $ — $ 7,788 Less: Undistributed earnings allocated to participating securities — — — (6,788) Reallocation of net income attributable to common stockholders (7,265) 7,265 — — Net income attributable to common stockholders – basic $ 8,030 $ 20,335 $ — $ 1,000 Denominator: Weighted average common shares outstanding – basic 14,087,401 35,667,048 — 10,178,598 Net income per share attributable to common stockholders – basic: $ 0.57 $ 0.57 $ — $ 0.10 Numerator: Net income attributable to common stockholders - diluted $ 7,146 $ 21,219 $ — $ 1,269 Denominator: Weighted average shares outstanding – basic 14,087,401 35,667,048 — 10,178,598 Options to purchase common stock 85,726 6,653,755 — 3,893,650 Restricted stock 23,222 — — — Employee stock purchase plan shares 58,715 — — — Weighted average shares outstanding – diluted 14,255,064 42,320,803 — 14,072,248 Net income per share attributable to common stockholders – diluted $ 0.50 $ 0.50 $ — $ 0.09
Schedule of Antidilutive Securities Excluded from Computation of Earnings per Share	The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net income per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: Three Months Ended September 30, 2021 2020 Class A Class B Class A Class B Options to purchase common stock 892,639 — — — Common stock issuable upon conversion of convertible preferred stock — — — 33,443,969 Total excludable from net income per share attributable to common stockholders – diluted 892,639 — — 33,443,969 The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net income per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: Nine months ended September 30, 2021 2020 Class A Class B Class A Class B Options to purchase common stock 668,294 — — 1,128,642 Common stock issuable upon conversion of convertible preferred stock — — — 33,443,969 Total excludable from net income per share attributable to common stockholders – diluted 668,294 — — 34,572,611

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	The following table represents total revenue by geographic area based on the publisher’s billing address (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 United States $ 36,451 $ 24,412 $ 93,935 $ 60,962 EMEA 15,552 8,925 41,306 20,454 APAC 4,909 3,777 13,245 9,396 Rest of the world 1,174 683 2,866 1,694 Total $ 58,086 $ 37,797 $ 151,352 $ 92,506 The Company’s long-lived assets, net by geographic area are summarized as follows (in thousands): September 30, December 31, 2020 United States $ 43,255 $ 24,580 Rest of the world 8,672 5,464 Total $ 51,927 $ 30,044

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies - Initial Public Offering (Details) $ / shares in Units, $ in Millions	Dec. 11, 2020USD ($)$ / sharesshares
Class B
Schedule of Equity Method Investments [Line Items]
Convertible preferred stock, shares issued upon conversion	33,443,969
IPO
Schedule of Equity Method Investments [Line Items]
Sale of stock, number of shares issued in transaction	2,655,000
Sale of stock, price per share (in usd per share) | $ / shares	$ 20
Sale of stock, consideration received on transaction | $	$ 45
Deferred offering costs | $	$ 4.4
IPO | Class B
Schedule of Equity Method Investments [Line Items]
Convertible preferred stock, shares issued upon conversion	33,443,969

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Concentration Risk Percentage (Details) - Customer Concentration Risk - Accounts Receivable	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
One Publisher
Concentration Risk [Line Items]
Concentration risk, percentage	17.00%	18.00%	18.00%	21.00%
Buyer One
Concentration Risk [Line Items]
Concentration risk, percentage			28.00%		33.00%
Buyer Two
Concentration Risk [Line Items]
Concentration risk, percentage			20.00%		14.00%
Buyer Three
Concentration Risk [Line Items]
Concentration risk, percentage			10.00%		13.00%
Buyer Four
Concentration Risk [Line Items]
Concentration risk, percentage					11.00%

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value	$ 47,355	$ 19,793
Total Financial Assets	118,985	39,454
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	65,128	12,462
Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	6,502
Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	71,630	19,661
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value		7,199
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value	0	0
Total Financial Assets	65,128	12,462
Fair Value, Inputs, Level 1 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	65,128	12,462
Fair Value, Inputs, Level 1 | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0
Fair Value, Inputs, Level 1 | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	65,128	12,462
Fair Value, Inputs, Level 1 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value		0
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value	47,355	19,793
Total Financial Assets	53,857	26,992
Fair Value, Inputs, Level 2 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0	0
Fair Value, Inputs, Level 2 | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	6,502
Fair Value, Inputs, Level 2 | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	6,502	7,199
Fair Value, Inputs, Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value		7,199
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value	0	0
Total Financial Assets	0	0
Fair Value, Inputs, Level 3 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0	0
Fair Value, Inputs, Level 3 | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0
Fair Value, Inputs, Level 3 | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0	0
Fair Value, Inputs, Level 3 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value		0
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value	47,355
Commercial paper | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value	0	0
Commercial paper | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value	47,355	10,794
Commercial paper | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value	$ 0	0
U.S. Treasury and government debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value		8,999
U.S. Treasury and government debt securities | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value		0
U.S. Treasury and government debt securities | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value		8,999
U.S. Treasury and government debt securities | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities, fair value		$ 0

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 47,355	$ 19,792
Gross Unrealized Gains	0	1
Gross Unrealized Loss	0	0
Marketable securities	47,355	19,793
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	47,355	10,794
Gross Unrealized Gains	0	0
Gross Unrealized Loss	0	0
Marketable securities	$ 47,355	10,794
U.S. Treasury and government debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		8,998
Gross Unrealized Gains		1
Gross Unrealized Loss		0
Marketable securities		$ 8,999

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property, Equipment and Software, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, equipment and software, gross	$ 126,007	$ 89,147
Less: accumulated depreciation and amortization	(74,080)	(59,103)
Property, equipment and software - net	51,927	30,044
Internal-use software
Property, Plant and Equipment [Line Items]
Property, equipment and software, gross	31,674	24,513
Network hardware, computer equipment and software
Property, Plant and Equipment [Line Items]
Property, equipment and software, gross	91,615	62,764
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, equipment and software, gross	2,098	1,249
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, equipment and software, gross	$ 620	$ 621

Balance Sheet Components - Narr

Balance Sheet Components - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 4.4	$ 2.6	$ 10.7	$ 7.2
Capitalized computer software additions	2.6	1.6	7.2	5.1
Internal-use software
Property, Plant and Equipment [Line Items]
Amortization	$ 1.9	$ 1.6	$ 5.3	$ 4.4

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Accounts Payable (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Payable to publishers	$ 185,530	$ 168,673
Other	9,802	8,058
Total accounts payable	$ 195,332	$ 176,731

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued compensation	$ 13,205	$ 13,352
Accrued and other current liabilities	4,456	1,492
Accrued liabilities	$ 17,661	$ 14,844

Loan and Security Agreement (De

Loan and Security Agreement (Details) - Revolving Credit Facility - Silicon Valley Bank $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 25
Line of credit facility, borrowing capacity, percentage of eligible accounts receivable, net,	80.00%
Debt instrument, interest rate	3.25%
Line of credit facility, unused capacity, commitment fee percentage	0.40%
Line of credit facility, borrowing capacity, unused capacity fee, closing balance threshold	$ 5
Debt instrument, covenant, quick ratio, minimum	1

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Commitments (Details) $ in Thousands	Sep. 30, 2021USD ($)
Leases
2021 (for remaining 3 months)	$ 488
2022	1,017
2023	106
2024	0
Total future minimum commitments, net	1,611
Other Contractual Obligations
2021 (for remaining 3 months)	2,261
2022	9,255
2023	7,234
2024	3,877
Total future minimum commitments, net	$ 22,627

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Operating leases, rent expense, net	$ 0.5	$ 0.6	$ 1.6	$ 1.9
Sublease income		$ 0.1		$ 0.4
Letters of credit outstanding, amount	$ 0.7		$ 0.7		$ 0.7

Convertible Preferred Stock (De

Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Dec. 11, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Preferred Units [Line Items]
Preferred stock shares authorized	10,000,000			10,000,000	10,000,000
Preferred stock par value (in usd per share)	$ 0.0001			$ 0.0001	$ 0.0001
Class B
Preferred Units [Line Items]
Convertible preferred stock, shares issued upon conversion					33,443,969
Convertible Preferred Stock
Preferred Units [Line Items]
Temporary equity, carrying amount, attributable to parent	$ 0	$ 0	$ 0	$ 0	$ 61,200	$ 61,216	$ 61,216	$ 61,216	$ 61,216

Stockholders_ Notes Receivabl_2

Stockholders’ Notes Receivable and Redeemable Common Stock (Details) - USD ($) $ in Thousands, shares in Millions	3 Months Ended
	Sep. 30, 2020	Aug. 31, 2018
Class of Stock [Line Items]
Temporary equity, common stock, shares issued		1.6
2.42% due August 2021 | Notes Payable, Other Payables
Class of Stock [Line Items]
Debt instrument, face amount		$ 4,000
Debt instrument, interest rate		2.42%
Redeemable Common Stock
Class of Stock [Line Items]
Reclassification of redeemable common stock	$ 19,025

Stockholders_ Equity and Stoc_3

Stockholders’ Equity and Stock Option Plans - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 11, 2020	Nov. 30, 2020
Class of Stock [Line Items]
Share-based payment arrangement, nonvested award, excluding option, cost not yet recognized, amount	$ 14.7
Discount from market price, purchase date	85.00%
Amount withheld for employee stock purchase plan	$ 1.5
Share-based Payment Arrangement, Option
Class of Stock [Line Items]
Share-based payment arrangement, nonvested award, option, cost not yet recognized, amount	$ 19
Share-based payment arrangement, nonvested award, cost not yet recognized, period for recognition	2 years 10 months 28 days
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Share-based payment arrangement, nonvested award, cost not yet recognized, period for recognition	3 years 5 months 4 days
Employee Stock
Class of Stock [Line Items]
Common stock reserved for issuance (in shares)	834,866
Share-based payment arrangement, nonvested award, cost not yet recognized, period for recognition	8 months 1 day
Share-based payment arrangement, nonvested award, excluding option, cost not yet recognized, amount	$ 2.4
Percentage of outstanding stock maximum	1.00%
Class A
Class of Stock [Line Items]
Common stock shares authorized	1,000,000,000	1,000,000,000	1,000,000,000
Common stock par value (in usd per share)	$ 0.0001	$ 0.0001	$ 0.0001
Common stock reserved for issuance (in shares)	6,414,228
Issuance of common stock related to employee stock purchase plan (in shares)	155,015
Class A | Employee Stock
Class of Stock [Line Items]
Common stock reserved for issuance (in shares)				500,000
Number of shares authorized	7,500,000
Class B
Class of Stock [Line Items]
Common stock shares authorized	1,000,000,000	1,000,000,000	1,000,000,000
Common stock par value (in usd per share)	$ 0.0001	$ 0.0001	$ 0.0001

Stockholders_ Equity and Stoc_4

Stockholders’ Equity and Stock Option Plans - Summary of Stock Option Activity and Related Information (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Number of Shares Underlying Outstanding Options
Beginning balance (in shares) | shares	8,459,969
Options granted (in shares) | shares	660,466
Options exercised (in shares) | shares	(1,694,511)
Options canceled (in shares) | shares	(27,094)
Ending balance (in shares) | shares	7,398,830	8,459,969
Vested (in shares) | shares	4,822,778
Weighted-Average Exercise Price
Beginning balance (in usd per share) | $ / shares	$ 2.53
Options granted (in usd per share) | $ / shares	36.74
Options exercised (in usd per share) | $ / shares	1.96
Options canceled (in usd per share) | $ / shares	7.96
Ending balance (in usd per share) | $ / shares	5.69	$ 2.53
Vested (in usd per share) | $ / shares	$ 3.12
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term (years)	7 years 3 days	6 years 9 months 29 days
Weighted average remaining contractual term vested (in years)	6 years 1 month 17 days
Aggregate intrinsic value, awards outstanding | $	$ 159,659	$ 215,144
Aggregate intrinsic value, vested | $	$ 113,146

Stockholders_ Equity and Stoc_5

Stockholders’ Equity and Stock Option Plans - Summary of Restricted Stock Units and Related Information (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Number of Shares Underlying Outstanding Options
Unvested beginning balance (in shares) | shares	0
Granted (in shares) | shares	507,406
Vested (in shares) | shares	(43,812)
Canceled/Forfeited (in shares) | shares	(11,281)
Unvested ending balance (in shares) | shares	452,313
Weighted-Average Exercise Price
Unvested beginning balance (in usd per share) | $ / shares	$ 0
Granted (in usd per share) | $ / shares	35.45
Vested (in usd per share) | $ / shares	37.92
Canceled/Forfeited (in usd per share) | $ / shares	32.70
Unvested ending balance (in usd per share) | $ / shares	$ 35.28

Stockholders_ Equity and Stoc_6

Stockholders’ Equity and Stock Option Plans - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 3,714	$ 1,444	$ 10,508	$ 2,439
Tax benefit from stock-based compensation	(521)	(206)	(1,401)	(293)
Total stock-based compensation, net of tax effect	3,193	1,238	9,107	2,146
Cost of revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	233	10	605	30
Technology and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	586	222	1,646	377
Sales and marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	1,388	358	3,839	721
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 1,507	$ 854	$ 4,418	$ 1,311

Net Income Per Share Attribut_3

Net Income Per Share Attributable to Common Stockholders - Basic and Diluted Net Income per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income	$ 13,526	$ 9,921	$ 4,918	$ 6,231	$ 653	$ 904	$ 28,365	$ 7,788
Denominator:
Weighted average common shares outstanding – basic	50,559,636			10,335,359			49,754,449	10,178,598
Net income per share attributable to common stockholders – basic: (in usd per share)	$ 0.27			$ 0.12			$ 0.57	$ 0.10
Denominator:
Weighted average common shares outstanding – basic	50,559,636			10,335,359			49,754,449	10,178,598
Weighted average shares outstanding – diluted	56,498,891			15,876,890			56,575,867	14,072,248
Net income per share attributable to common stockholders – diluted (in usd per share)	$ 0.24			$ 0.10			$ 0.50	$ 0.09
Class A
Numerator:
Net income	$ 7,294			$ 0			$ 15,295	$ 0
Less: Undistributed earnings allocated to participating securities	0			0			0	0
Reallocation of net income attributable to common stockholders	(1,229)			0			(7,265)	0
Net income attributable to common stockholders – basic	$ 6,065			$ 0			$ 8,030	$ 0
Denominator:
Weighted average common shares outstanding – basic	22,669,223			0			14,087,401	0
Net income per share attributable to common stockholders – basic: (in usd per share)	$ 0.27			$ 0			$ 0.57	$ 0
Numerator:
Net income attributable to common stockholders - diluted	$ 5,445			$ 0			$ 7,146	$ 0
Denominator:
Weighted average common shares outstanding – basic	22,669,223			0			14,087,401	0
Options to purchase common stock (in shares)	0			0			85,726	0
Restricted stock (in shares)	11,553			0			23,222	0
Employee stock purchase plan shares (in shares)	63,068			0			58,715	0
Weighted average shares outstanding – diluted	22,743,844			0			14,255,064	0
Net income per share attributable to common stockholders – diluted (in usd per share)	$ 0.24			$ 0			$ 0.50	$ 0
Class B
Numerator:
Net income	$ 6,232			$ 6,231			$ 13,070	$ 7,788
Less: Undistributed earnings allocated to participating securities	0			(5,035)			0	(6,788)
Reallocation of net income attributable to common stockholders	1,229			0			7,265	0
Net income attributable to common stockholders – basic	$ 7,461			$ 1,196			$ 20,335	$ 1,000
Denominator:
Weighted average common shares outstanding – basic	27,890,413			10,335,359			35,667,048	10,178,598
Net income per share attributable to common stockholders – basic: (in usd per share)	$ 0.27			$ 0.12			$ 0.57	$ 0.10
Numerator:
Net income attributable to common stockholders - diluted	$ 8,081			$ 1,630			$ 21,219	$ 1,269
Denominator:
Weighted average common shares outstanding – basic	27,890,413			10,335,359			35,667,048	10,178,598
Options to purchase common stock (in shares)	5,864,634			5,541,531			6,653,755	3,893,650
Restricted stock (in shares)	0			0			0	0
Employee stock purchase plan shares (in shares)	0			0			0	0
Weighted average shares outstanding – diluted	33,755,047			15,876,890			42,320,803	14,072,248
Net income per share attributable to common stockholders – diluted (in usd per share)	$ 0.24			$ 0.10			$ 0.50	$ 0.09

Net Income Per Share Attribut_4

Net Income Per Share Attributable to Common Stockholders - Schedule of Antidilutive Securities Excluded from Computation of Earnings per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Class A
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total excludable from net income per share attributable to common stockholders – diluted	892,639	0	668,294	0
Class A | Options to purchase common stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total excludable from net income per share attributable to common stockholders – diluted	892,639	0	668,294	0
Class A | Common stock issuable upon conversion of convertible preferred stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total excludable from net income per share attributable to common stockholders – diluted	0	0	0	0
Class B
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total excludable from net income per share attributable to common stockholders – diluted	0	33,443,969	0	34,572,611
Class B | Options to purchase common stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total excludable from net income per share attributable to common stockholders – diluted	0	0	0	1,128,642
Class B | Common stock issuable upon conversion of convertible preferred stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total excludable from net income per share attributable to common stockholders – diluted	0	33,443,969	0	33,443,969

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 799	$ 1,621	$ 2,695	$ 2,104
Effective income tax rate reconciliation, percent	9.00%	21.00%

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 58,086	$ 37,797	$ 151,352	$ 92,506
Total	51,927		51,927		$ 30,044
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	36,451	24,412	93,935	60,962
Total	43,255		43,255		24,580
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	15,552	8,925	41,306	20,454
APAC
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	4,909	3,777	13,245	9,396
Rest of the world
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	1,174	$ 683	2,866	$ 1,694
Total	$ 8,672		$ 8,672		$ 5,464

401(k) Plan - Narrative (Detail

401(k) Plan - Narrative (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Retirement Benefits [Abstract]
Defined contribution plan, maximum annual contributions per employee, percent	100.00%
Defined contribution plan, employer discretionary contribution amount	$ 0	$ 0

Subsequent Events (Details)

Subsequent Events (Details) $ in Millions	1 Months Ended
	Oct. 31, 2021USD ($)ft²	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Subsequent Event [Line Items]
Letters of credit outstanding, amount		$ 0.7	$ 0.7
Subsequent Event
Subsequent Event [Line Items]
Operating lease, area of headquarters | ft²	34,229
Annual lease payments	$ 3.4
Annual payment increase percentage	0.030
Letters of credit outstanding, amount	$ 3.5