Viant Technology (DSP) 10-Q 10 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 08, 2021
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--12-31
Entity Registrant Name	Viant Technology Inc.
Entity Central Index Key	0001828791
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	85-3447553
Entity File Number	001-40015
Entity Address, Address Line One	2722 Michelson Drive
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Irvine
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92612
Local Phone Number	861-8888
City Area Code	949
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	true
Entity Small Business	false
Entity Ex Transition Period	false
Entity Shell Company	false
Title of 12(b) Security	Class A common stock, par value $0.001 per share
Trading Symbol	DSP
Name of each exchange on which registered	NASDAQ
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		13,482,550
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		47,137,130

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash	$ 242,610	$ 9,629
Accounts receivable, net of allowances	69,612	89,767
Prepaid expenses and other current assets	4,195	4,487
Total current assets	316,417	103,883
Property, equipment, and software, net	22,650	13,829
Intangible assets, net	2,093	3,015
Goodwill	12,422	12,422
Other assets	388	371
Total assets	353,970	133,520
Current liabilities:
Accounts payable	24,652	29,763
Accrued liabilities	23,240	24,677
Accrued compensation	9,908	9,711
Current portion of long-term debt		3,353
Current portion of deferred revenue	1,457	2,725
Accrued member tax distributions	5	6,878
Other current liabilities	2,377	2,549
Total current liabilities	61,639	79,656
Long-term debt	17,500	20,182
Long-term portion of deferred revenue	5,433	5,612
Other long-term liabilities	570	453
Total liabilities	85,142	105,903
Commitments and contingencies (Note 12)
Convertible preferred units
2019 convertible preferred units, no par value; none issued and outstanding as of September 30, 2021 and 600,000 units authorized, issued and outstanding as of December 31, 2020; liquidation preference $5,444 as of December 31, 2020		7,500
Members' equity
Additional paid-in capital		92,187
Accumulated deficit		(72,070)
Stockholders’ equity
Preferred stock, $0.001 par value, 10,000,000 shares authorized, none issued and outstanding as of September 30, 2021
Additional paid-in capital	79,250
Accumulated deficit	(15,760)
Treasury stock, at cost; 408,318 shares as of September 30, 2021	(7,239)
Total stockholders' equity attributable to Viant Technology Inc./members' equity	56,312	20,117
Noncontrolling interests	212,516
Total equity	268,828	20,117
Total liabilities, convertible preferred units and stockholders' equity/members' equity	353,970	$ 133,520
Class A Common Stock
Stockholders’ equity
Common stock	14
Total equity	14
Class B Common Stock
Stockholders’ equity
Common stock	47
Total equity	$ 47

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Common units no par value		$ 0
Common units, units authorized		400,000
Common units, units issued	0	400,000
Common units, units outstanding	0	400,000
Preferred stock, par value per share	$ 0.001
Preferred stock, shares authorized	10,000,000
Preferred stock, shares issued	0
Preferred stock, shares outstanding	0
Treasury stock, shares	408,318
2019 Convertible Preferred Units
Convertible preferred units, no par value		$ 0
Convertible preferred units, units authorized		600,000
Convertible preferred units, units issued	0	600,000
Convertible preferred units, units outstanding	0	600,000
Convertible preferred units, liquidation preference		$ 5,444
Class A Common Stock
Common stock, par value per share	$ 0.001
Common stock, shares authorized	450,000,000
Common stock, shares issued	13,890,868
Common stock, shares outstanding	13,482,550
Class B Common Stock
Common stock, par value per share	$ 0.001
Common stock, shares authorized	150,000,000
Common stock, shares issued	47,137,130
Common stock, shares outstanding	47,137,130

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - 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	$ 50,857	$ 40,205	$ 141,412	$ 108,790
Operating expenses:
Platform operations	28,967	20,124	85,026	62,316
Sales and marketing	15,131	6,521	49,869	19,393
Technology and development	6,590	1,946	20,521	6,080
General and administrative	11,981	3,861	36,477	12,408
Total operating expenses	62,669	32,452	191,893	100,197
Income (loss) from operations	(11,812)	7,753	(50,481)	8,593
Interest expense, net	227	264	703	789
Other expense, net	121	11	53	27
Gain on extinguishment of debt			(6,110)
Total other expense (income), net	348	275	(5,354)	816
Net income (loss)	(12,160)	7,478	(45,127)	7,777
Less: Net loss attributable to noncontrolling interests	(9,623)		(35,829)
Net income (loss) attributable to Viant Technology Inc.	$ (2,537)	$ 7,478	$ (9,298)	$ 7,777
Earnings (loss) per Class A common stock/unit:
Basic	$ (0.20)	$ 7.48	$ (0.78)	$ 7.78
Diluted	$ (0.20)	$ 7.48	$ (0.78)	$ 7.78
Weighted-average Class A common stock/units outstanding:
Basic	12,489	400	11,894	400
Diluted	12,489	1,000	11,894	1,000

CONSOLIDATED STATEMENTS OF CONV

CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED UNITS AND MEMBERS' EQUITY/STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Convertible Preferred Units	Class A Common Stock	Class B Common Stock	Common Units	Additional Paid-in Capital	Accumulated Deficit	Total Members? Equity (Deficit)	Treasury Stock	Noncontrolling Interests
Temporary Equity, Balance at Dec. 31, 2019		$ 7,500
Temporary Equity, Balance, Share at Dec. 31, 2019		600,000
Balance at Dec. 31, 2019	$ 15,205					$ 92,187	$ (76,982)
Balance, Shares at Dec. 31, 2019					400,000
Accrued member tax distributions	(390)						(390)
Net income (loss)	329						329
Temporary Equity, Balance at Mar. 31, 2020		$ 7,500
Temporary Equity, Balance, Share at Mar. 31, 2020		600,000
Balance at Mar. 31, 2020	15,144					92,187	(77,043)
Balance, Shares at Mar. 31, 2020					400,000
Temporary Equity, Balance at Dec. 31, 2019		$ 7,500
Temporary Equity, Balance, Share at Dec. 31, 2019		600,000
Balance at Dec. 31, 2019	15,205					92,187	(76,982)
Balance, Shares at Dec. 31, 2019					400,000
Net income (loss)	7,777
Temporary Equity, Balance at Sep. 30, 2020		$ 7,500
Temporary Equity, Balance, Share at Sep. 30, 2020		600,000
Balance at Sep. 30, 2020	19,780					92,187	(72,407)
Balance, Shares at Sep. 30, 2020					400,000
Temporary Equity, Balance at Mar. 31, 2020		$ 7,500
Temporary Equity, Balance, Share at Mar. 31, 2020		600,000
Balance at Mar. 31, 2020	15,144					92,187	(77,043)
Balance, Shares at Mar. 31, 2020					400,000
Accrued member tax distributions	(356)						(356)
Net income (loss)	(30)						(30)
Temporary Equity, Balance at Jun. 30, 2020		$ 7,500
Temporary Equity, Balance, Share at Jun. 30, 2020		600,000
Balance at Jun. 30, 2020	14,758					92,187	(77,429)
Balance, Shares at Jun. 30, 2020					400,000
Accrued member tax distributions	(2,456)						(2,456)
Net income (loss)	7,478						7,478
Temporary Equity, Balance at Sep. 30, 2020		$ 7,500
Temporary Equity, Balance, Share at Sep. 30, 2020		600,000
Balance at Sep. 30, 2020	19,780					92,187	(72,407)
Balance, Shares at Sep. 30, 2020					400,000
Temporary Equity, Balance at Dec. 31, 2020		$ 7,500
Temporary Equity, Balance, Share at Dec. 31, 2020		600,000
Balance at Dec. 31, 2020	20,117							$ 20,117
Balance, Shares at Dec. 31, 2020					400,000
Net income prior to Reorganization Transactions	669							669
Effect of Reorganization Transactions	7,500			$ 49		28,237		(20,786)
Temporary Equity, Effect of Reorganization Transactions, Shares		(600,000)
Temporary Equity, Effect of Reorganization Transactions		$ (7,500)
Effect of Reorganization Transactions, Shares				48,936,000	(400,000)
Issuance of Class A common stock in initial public offering, net of underwriting and offering costs	228,185		$ 12	$ (2)		228,175
Issuance of Class A common stock in initial public offering, net of underwriting and offering costs, Shares			11,500,000	(1,500,000)
Allocation of equity to noncontrolling interests						(208,587)				$ 208,587
Accrued member tax distributions	75					75
Stock-based compensation	19,756					19,756
Net loss subsequent to Reorganization Transactions	(15,539)						(3,104)			(12,435)
Balance at Mar. 31, 2021	260,763		$ 12	$ 47		67,656	(3,104)			196,152
Balance, Shares at Mar. 31, 2021			11,500,000	47,436,000
Temporary Equity, Balance at Dec. 31, 2020		$ 7,500
Temporary Equity, Balance, Share at Dec. 31, 2020		600,000
Balance at Dec. 31, 2020	20,117							$ 20,117
Balance, Shares at Dec. 31, 2020					400,000
Net income (loss)	(45,127)
Balance at Sep. 30, 2021	268,828		$ 14	$ 47		79,250	(15,760)		$ (7,239)	212,516
Balance, Shares at Sep. 30, 2021			13,891,000	47,137,000					(408)
Balance at Mar. 31, 2021	260,763		$ 12	$ 47		67,656	(3,104)			196,152
Balance, Shares at Mar. 31, 2021			11,500,000	47,436,000
Accrued member tax distributions	(192)					(192)
Stock-based compensation	34,576					34,576
Net income (loss)	(18,095)						(3,655)			(14,440)
Balance at Jun. 30, 2021	277,052		$ 12	$ 47		102,040	(6,759)			181,712
Balance, Shares at Jun. 30, 2021			11,500,000	47,436,000
Exchange of Class B common stock for Class A common stock, Shares			299,000	(299,000)
Issuance of common stock in connection with equity-based compensation plans			$ 2			(2)
Issuance of common stock in connection with equity-based compensation plans, Shares			2,092,000
Repurchase of treasury shares in connection with the taxes paid related to net share settlement of equity awards	(13,703)								$ (13,703)
Repurchase of treasury shares in connection with the taxes paid related to net share settlement of equity awards, Shares									(773)
Reissuance of treasury stock in connection with equity-based compensation plans							(6,464)		$ 6,464
Reissuance of treasury stock in connection with equity-based compensation plans, Shares									365
Allocation of equity to noncontrolling interests						(40,427)				40,427
Accrued member tax distributions	(337)					(337)
Stock-based compensation	17,976					17,976
Net income (loss)	(12,160)						(2,537)			(9,623)
Balance at Sep. 30, 2021	$ 268,828		$ 14	$ 47		$ 79,250	$ (15,760)		$ (7,239)	$ 212,516
Balance, Shares at Sep. 30, 2021			13,891,000	47,137,000					(408)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income (loss)	$ (45,127)	$ 7,777
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	8,024	7,654
Stock-based compensation	62,192
Provision for (recovery of) doubtful accounts	(161)	(236)
Loss on disposal of assets	148	13
Gain on extinguishment of debt	(6,110)
Changes in operating assets and liabilities:
Accounts receivable	20,316	6,686
Prepaid expenses and other assets	(1,960)	(305)
Accounts payable	(4,816)	1,703
Accrued liabilities	(1,118)	(6,518)
Accrued compensation	198	(280)
Deferred revenue	(1,446)	(1,578)
Other liabilities	(55)	(734)
Net cash provided by operating activities	30,085	14,182
Cash flows from investing activities:
Purchases of property and equipment	(386)	(372)
Capitalized software development costs	(5,577)	(5,456)
Net cash used in investing activities	(5,963)	(5,828)
Cash flows from financing activities:
Proceeds from Paycheck Protection Program Loan		6,035
Proceeds from issuance of common stock, net of underwriting discounts	232,500
Payment of member tax distributions	(7,330)	(5,539)
Payment of offering costs	(2,608)	(119)
Taxes paid related to net share settlement of equity awards	(13,703)
Net cash provided by financing activities	208,859	377
Net increase in cash	232,981	8,731
Cash at beginning of period	9,629	4,815
Cash at end of period	242,610	13,546
Supplemental disclosure of cash flow information:
Cash paid for interest	546	856
Supplemental disclosure of non-cash investing and financing activities:
Stock-based compensation included in capitalized software development costs	10,116
Accrued member tax distributions	5
Capitalized assets financed by accounts payable and accrued liabilities		$ 401
Noncash gain on extinguishment of debt related to Paycheck Protection Program loan	$ 6,110

Nature of Operations

Nature of Operations	9 Months Ended
	Sep. 30, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Operations	1. Nature of Operations Viant for the purpose of facilitating an Initial Public Offering (“IPO”) and other related transactions. On February 9, 2021, the SEC declared effective the Company’s Form S-1 related to the IPO of its Class A common stock. The closing date of the IPO was February 12, 2021, and in connection with the closing and the corporate reorganization (the “Reorganization Transactions”), the following actions were taken: • • The limited liability company agreement of Viant Technology LLC was amended and restated (as amended and restated, the “Viant Technology LLC Agreement”) to, among other things, provide for Class A units and Class B units and appoint the Company as the sole managing member of Viant Technology LLC; • The Viant Technology LLC Agreement classified the interests acquired by the Company as Class A units, reclassified the interests held by the continuing members of Viant Technology LLC as Class B units, and permits the continuing members of Viant Technology LLC to exchange Class B units for shares of Class A common stock on a one-for-one basis or, at the election of Viant Technology Inc., for cash at the current fair value on the date of the exchange . Immediately following such reclassification, the continuing members held 48,935,559 Class B units. For each membership unit of Viant Technology LLC that was reclassified as a Class B unit, the Company issued one corresponding share of our Class B common stock to the continuing members, or 48,935,559 shares of Class B common stock in total; • The Company issued and sold 10,000,000 shares of its Class A common stock to the underwriters at an IPO price of $25.00 per share, for gross proceeds of $250.0 million before deducting underwriting discounts and commissions of $17.5 million; • The Company used the net proceeds of $232.5 million to acquire 10,000,000 newly issued Class A units of Viant Technology LLC at a per-unit price equal to the per-share price paid by the underwriters for shares of our Class A common stock; • The underwriters exercised their option to purchase 1,500,000 additional shares of Class A common stock from the selling stockholders. The Company did not receive any proceeds from the sale of shares by the selling stockholders. Pursuant to such exercise, the selling stockholders exchanged the corresponding number of Class B units for the shares of Class A common stock, the corresponding number of shares of Class B common stock were automatically retired, and 1,500,000 Class A units were issued to the Company; • The Class B stockholders and Class A stockholders initially had 80.5% and 19.5%, respectively, of the combined voting power of the Company’s common stock. The Class A common stock outstanding represents 100% of the rights of the holders of all classes of the Company’s outstanding common stock to share in distributions from the Company, except for the right of Class B stockholders to receive the par value of the Class B common stock upon our liquidation, dissolution or winding up or an exchange of Class B units; • • Immediately following the closing of the IPO, Viant Technology LLC is the predecessor of the Company for financial reporting purposes. The Company is a holding company, and its sole material asset is its equity interest in Viant Technology LLC. As the sole managing member of Viant Technology LLC, the Company operates and controls all of the business and affairs of Viant Technology LLC. The Reorganization Transactions are accounted for as a reorganization of entities under common control. As a result, the condensed consolidated financial statements of the Company recognize the assets and liabilities received in the Reorganization Transactions at their historical carrying amounts, as reflected in the historical consolidated financial statements of Viant Technology LLC. The Company consolidates Viant Technology LLC on its condensed consolidated financial statements and records a noncontrolling interest related to the Class B units held by the Class B stockholders on its condensed consolidated balance sheet and statement of operations.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Basis Of Presentation And Summary Of Significant Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	2. Basis of Presentation Basis of Presentation The condensed consolidated financial statements for interim financial information which are unaudited Viant Technology LLC is considered a variable interest entity, or VIE. The Company is the primary beneficiary and sole managing member of Viant Technology LLC and has decision making authority that significantly affects the economic performance of the entity. As a result, the Company consolidates Viant Technology LLC. All intercompany balances and transactions have been eliminated in consolidation Viant Technology LLC has been determined to be the predecessor for accounting purposes and, accordingly, the condensed consolidated financial statements for periods prior to the IPO and the related organizational transactions have been adjusted to combine the previously separate entities for presentation purposes. Amounts for the period from January 1, 2020 through February 11, 2021 presented in the condensed consolidated financial statements and notes to condensed consolidated financial statements herein represent the historical operations of Viant Technology LLC. The amounts as of September 30, 2021 and for the period from February 12, 2021 reflect the consolidated operations of the Company. Management believes that the accompanying condensed consolidated financial statements reflect the adjustments necessary for the fair statement of its condensed consolidated balance sheet as of September 30, 2021, results of operations for the three and nine months ended September 30, 2021 and 2020, and cash flows for the nine months ended September 30, 2021 and 2020. The condensed consolidated balance sheet as of December 31, 2020 was derived from the audited annual financial statements but does not contain all of the footnote disclosures from the annual financial statements. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with GAAP have been omitted. Accordingly, these condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and related notes included in its Annual Report on Form 10-K for the year ended December 31, 2020. The condensed consolidated results of operations for the three and nine months ended September 30, 2021 are not necessarily indicative of the results to be expected for the year ending December 31, 2021, or for any other future annual or interim period. Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. On an on-going basis, management evaluates its estimates, primarily those related to revenue recognition, stock-based compensation, income taxes, allowances for doubtful accounts, the useful lives of capitalized software development costs and other property, equipment and software and assumptions used in the impairment analyses of long-lived assets and goodwill. These estimates are based on historical data and experience, as well as various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying amount of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. As of September 30, 2021, the impact of the COVID-19 pandemic on our business continues to evolve. As a result, many of our estimates and assumptions consider macro-economic factors in the market, which require increased judgment and carry a higher degree of variability and volatility. As events continue to evolve and additional information becomes available, our estimates may change materially in future periods. Fair Value of Financial Instruments Financial instruments consist of cash, accounts receivable, accounts payable, accrued liabilities and debt. The carrying amounts of the Company’s current financial assets and current financial liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. Stock-Based Compensation Stock-based compensation relates to equity awards granted under the Company’s 2021 LTIP, which is measured and recognized in the condensed consolidated financial statements based on the fair value of the equity awards granted. Since inception of the 2021 LTIP, the Company has only granted restricted stock units (“RSUs”) and nonqualified stock options. The fair value of RSUs is calculated using the closing market price of the Company’s common stock on the date of grant. The fair value of non-qualified stock options is estimated using the Black Scholes option pricing model. The Black Scholes option pricing model is impacted by the fair value of the Company’s common stock, as well as changes in certain assumptions, including but not limited to, the expected common stock price volatility over the term of the nonqualified stock options, the expected term of the nonqualified stock options, the risk-free interest rate, and the expected dividend yield. A portion of RSUs granted as of September 30, 2021 to certain employees and board members, pursuant to the 2021 LTIP, vested upon expiration of the 180 day IPO lock-up period during the three months ended September 30, 2021. The remainder of employee granted RSUs and nonqualified stock options will vest through the applicable vesting dates, subject to continued employment for employee grants. RSUs awarded to board members upon their appointment will vest on the third anniversary of the grant date and RSUs awarded to board members annually will vest on the first anniversary of the grant date. Comprehensive Income (Loss) For the periods presented, net income (loss) is equal to comprehensive income (loss). Noncontrolling Interests The noncontrolling interests represent the economic interests of Viant Technology LLC held by Class B common stockholders. Income or loss is attributed to the noncontrolling interests based on the weighted average LLC interests outstanding during the period. The noncontrolling interests’ ownership percentage can fluctuate over time as Class A common shares are issued in connection with the 2021 LTIP or as the Class B common stockholders elect to exchange their Class B common stock (and corresponding Class B units of Viant Technology LLC) for Class A common stock. Earnings (Loss) Basic number of The Company’s RSUs, nonqualified stock options and shares of Class B common stock do not share in the earnings or losses of the Company and are therefore not participating securities. As such, separate presentation of basic and diluted earnings (loss) per share of RSUs, nonqualified stock options and Class B common stock under the two-class method has not been presented. Diluted have an anti-dilutive effect. Shares of our Class B common stock , RSUs , and nonqualified stock options are considered potentially dilutive shares of Class A common stock; however, related amounts have been excluded from the computation of diluted earnings (loss) per share of Class A common stock because the effect would have been anti-dilutive under the if-converted method. Earnings (Loss) Per Unit Basic earnings (loss) per unit is calculated by dividing the earnings (loss) attributable to common unitholders by the number of weighted-average common units outstanding. The Company applies the two-class method to allocate earnings between common and convertible preferred units. Diluted earnings (loss) per unit adjusts the basic earnings (loss) per unit attributable to common unitholders and the weighted-average number of units of common units outstanding for the potential dilutive impact of common units, using the treasury-stock method, and convertible preferred units using the if-converted method. Diluted earnings (loss) per unit considers the impact of potentially dilutive securities except in periods in which there is a loss because the inclusion of the potential common units would have an anti-dilutive effect. Accounts Receivable, The following (in thousands) Balance as of December 31, 2020 $ 335 Recovery of doubtful accounts (194 ) Write-offs, net of recoveries (126 ) Balance as of March 31, 2021 $ 15 Recovery of doubtful accounts (6 ) Write-offs, net of recoveries (1 ) Balance as of June 30, 2021 $ 8 Provision for doubtful accounts 39 Write-offs, net of recoveries (23 ) Balance as of September 30, 2021 $ 24 Deferred Deferred $2.2 million . Upon of $4.3 million Concentration Financial ’s As of September 30, 2021, no individual customers accounted for more than 10% of consolidated accounts receivable. As of December 31, 2020, one individual customer accounted for 13.7% of consolidated accounts receivable. The following table provides the Company’s concentrations of credit risk with respect to individual customers as a percentage of the Company’s total revenues: Three Months Ended September 30, Nine Months Ended September 30, Individual Customer 2021 2020 2021 2020 A * 10.4 % * * * Less than 10% of total revenues. The following table provides the Company’s concentrations of credit risk with respect to advertising agency holding companies as a percentage of the Company’s total revenues: Three Months Ended September 30, Nine Months Ended September 30, Advertising Agency Holding Company 2021 2020 2021 2020 A * 12.2 % 11.8 % 10.3 % B 16.3 % * 10.2 % 10.4 % C * 14.6 % * 14.8 % * Less than 10% of total revenues. As of September 30, 2021, one individual supplier accounted for 16.5% of consolidated accounts payable and accrued liabilities. As of December 31, 2020, three suppliers accounted for 15.5%, 11.5%, and 10.9% of consolidated accounts payable and accrued liabilities, respectively. Income The Company is the managing member of Viant Technology LLC and, as a result, consolidates the financial results of Viant Technology LLC in the unaudited condensed consolidated financial statements. Viant Technology LLC is a pass-through entity for U.S. federal and most applicable state and local income tax purposes following a corporate reorganization effected in connection with our IPO. As an entity classified as a partnership for tax purposes, Viant Technology LLC is not subject to U.S. federal and certain state and local income taxes. Any taxable income or loss generated by Viant Technology LLC is passed through to, and included in the taxable income or loss of its members, including us. The Company is taxed as a corporation and pays corporate federal, state and local taxes with respect to income allocated from Viant Technology LLC, based on Viant Technology Inc.'s 22.2% economic interest in Viant Technology LLC as of September 30, 2021. The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities (“DTAs” and “DTLs”) for the expected future tax consequences of events that have been included in the financial statements. Under this method, we determine DTAs and DTLs on the basis of the differences between the financial statement and tax bases of assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on DTAs and DTLs is recognized in income in the period that includes the enactment date. We recognize DTAs to the extent that we believe that these assets are more likely than not to be realized. In making such a determination, we consider all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, carryback potential if permitted under the tax law, and results of recent operations. If we determine that we would be able to realize our DTAs in the future in excess of their net recorded amount, we would make an adjustment to the DTA valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions in accordance with ASC 740 on the basis of a two-step process in which (1) we determine whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, we recognize the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. Tax Receivable Agreement The Company expects to obtain an increase in its share of tax basis in the net assets of Viant Technology LLC when Class B units are exchanged by the holders of Class B units for shares of Class A common stock of the Company and upon other qualifying transactions. Each change in outstanding shares of Class A common stock of the Company results in a corresponding increase or decrease in the Company's ownership of Class A units of Viant Technology LLC. The Company intends to treat any exchanges of Class B units as direct purchases of LLC interests for U.S. federal income tax purposes. These increases in tax basis may reduce the amounts that the Company would otherwise pay in the future to various taxing authorities. They may also decrease gains (or increase losses) on future dispositions of certain capital assets to the extent tax basis is allocated to those capital assets. In connection with the IPO, the Company entered into a Tax Receivable Agreement (“TRA”) with Viant Technology LLC and the holders of Class B units of Viant Technology LLC (the “Members”). In the event that such parties exchange any or all of their Class B units for Class A common stock, the TRA requires the Company to make payments to such holders for 85% of the tax benefits realized, or in some cases deemed to be realized, by the Company by such exchange as a result of (i) increases in the Company’s tax basis of its ownership interest in the net assets of Viant Technology LLC resulting from any redemptions or exchanges of noncontrolling interest, (ii) tax basis increases attributable to payments made under the TRA, and (iii) deductions attributable to imputed interest pursuant to the TRA (the “TRA Payments”). The annual tax benefits are computed by calculating the income taxes due, including such tax benefits, and the income taxes due without such benefits. The Company expects to benefit from the remaining 15 % of any tax benefits that it may actually realize. The TRA Payments are not conditioned upon any continued ownership interest in Viant Technology LLC or the Company. To the extent that the Company is unable to timely make payments under the TRA for any reason, such payments generally will be deferred and will accrue interest until paid. The TRA provides that if (i) certain mergers, asset sales, other forms of business combinations, or other changes of control were to occur, (ii) there is a material breach of any material obligations under the TRA, or (iii) the Company elects an early termination of the TRA, then the TRA will terminate and the Company's obligations, or the Company's successor’s obligations, under the TRA will accelerate and become due and payable, based on certain assumptions, including an assumption that the Company would have sufficient taxable income to fully utilize all potential future tax benefits that are subject to the TRA and that any Class B units that have not been exchanged are deemed exchanged for the fair market value of the Company's Class A common stock at the time of termination Treasury Stock We account for treasury stock under the cost method. When treasury stock Recent Issued On April The Company has elected condensed In February Financial Accounting Standards Board (“ Topic 842 will materially affect our consolidated balance sheet . We plan to adopt Topic 842 effective January 1, 202 2 and are currently evaluating the use of optional practical expedients. In June 2016, the condensed In October 2020, the FASB issued ASU No. 2020-10, Codification Improvements , The guidance is effective for the Company’s annual reporting period beginning after December 15, 2021 and interim reporting periods within the annual period beginning after December 15, 2022. The Company is currently assessing the impact this guidance will have on the condensed consolidated financial statements. In May 2021, the FASB issued ASU No. 2021-04, Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation—Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40). The purpose of ASU 2021-04 is to clarify and reduce diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options that remain equity classified after modification or exchange. The ASU requires issuers to account for modifications or exchanges of freestanding equity-classified written call options that remain equity classified after the modification or exchange based on the economic substance of the modification or exchange. In accordance with ASU 2021-04, an issuer determines the accounting for the modification or exchange based on whether the transaction was done to issue equity, to issue or modify debt, or for other reasons. The guidance is effective for the Company’s annual reporting period beginning after December 15, 2021 and interim reporting periods within that annual reporting period. The Company is currently assessing the impact this guidance will have on the condensed consolidated financial statements. Recent Adopted In September prospectively In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes ("ASU 2019-12"). ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This guidance is effective for the Company’s annual reporting period beginning after December 15, 2020. The Company adopted ASU 2019-12 prospectively on January 1, 2021, and the adoption of this ASU did not have a material impact on the condensed consolidated financial statements.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2021
Revenue From Contract With Customer [Abstract]
Revenue	3. Revenue The disaggregation Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) (in thousands) Over-time revenue $ 1,136 $ 1,081 $ 3,344 $ 3,485 Point-in-time revenue 49,721 39,124 138,068 105,305 Total revenue $ 50,857 $ 40,205 $ 141,412 $ 108,790 Remaining 6.9 n n During the nine months ended September 30, 2021, we recognized $ 1.4

Property, Equipment and Softwar

Property, Equipment and Software, Net	9 Months Ended
	Sep. 30, 2021
Property Plant And Equipment [Abstract]
Property, Equipment and Software, Net	4. Property, Major As of September 30, As of December 31, 2021 2020 (in thousands) Capitalized software development costs $ 59,156 $ 43,627 Computer equipment 1,827 1,575 Purchased software 32 32 Furniture, fixtures and office equipment 1,149 1,087 Leasehold improvements 2,161 2,115 Total property, equipment and software 64,325 48,436 Less: Accumulated depreciation (41,675 ) (34,607 ) Total property, equipment and software, net $ 22,650 $ 13,829 Depreciation Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) (in thousands) Platform operations $ 2,080 $ 1,619 $ 5,424 $ 5,059 Sales and marketing — — — — Technology and development 421 403 1,185 1,206 General and administrative 164 171 494 468 Total $ 2,665 $ 2,193 $ 7,103 $ 6,733 For the three months ended September 30, 2021 and 2020, total interest cost incurred was $ 0.2 0.3 0.7 0.8

Intangible Assets, Net

Intangible Assets, Net	9 Months Ended
	Sep. 30, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets, Net	5. Intangible The balances As of September 30, 2021 Remaining Weighted Average Useful Life Gross Amount Accumulated Amortization Net Carrying Amount (in years) (in thousands) Developed technology 1.3 $ 4,927 $ (3,994 ) $ 933 Customer relationships 2.3 2,300 (1,533 ) 767 Trademarks/tradenames 4.0 1,400 (1,007 ) 393 Total $ 8,627 $ (6,534 ) $ 2,093 As of December 31, 2020 Remaining Weighted Average Useful Life Gross Amount Accumulated Amortization Net Carrying Amount (in years) (in thousands) Developed technology 2.1 $ 4,927 $ (3,469 ) $ 1,458 Customer relationships 3.1 2,300 (1,287 ) 1,013 Trademarks/tradenames 4.2 1,400 (856 ) 544 Total $ 8,627 $ (5,612 ) $ 3,015 Amortization condensed Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) (in thousands) Platform operations $ 175 $ 175 $ 525 $ 525 Sales and marketing — — — — Technology and development — — — — General and administrative 132 132 396 396 Total $ 307 $ 307 $ 921 $ 921 Estimated amortization As of September 30, 2021 Year (in thousands) Remainder of 2021 $ 308 2022 1,119 2023 467 2024 107 2025 80 Thereafter 12 Total $ 2,093

Accrued Liabilities

Accrued Liabilities	9 Months Ended
	Sep. 30, 2021
Payables And Accruals [Abstract]
Accrued Liabilities	6. Accrued Liabilities The Company’s As of September 30, As of December 31, 2021 2020 (in thousands) Accrued traffic acquisition costs $ 20,922 $ 22,667 Other accrued liabilities 2,318 2,010 Total accrued liabilities $ 23,240 $ 24,677

Long-Term Debt and Revolving Cr

Long-Term Debt and Revolving Credit Facility	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Long-Term Debt and Revolving Credit Facility	7. Long-Term Debt and Revolving Credit The Company’s As of September 30, As of December 31, 2021 2020 (in thousands) Revolving credit facility $ 17,500 $ 17,500 Paycheck Protection Program Loan — 6,035 Total debt 17,500 23,535 Less: Current portion of long-term debt — (3,353 ) Total long-term debt $ 17,500 $ 20,182 As of December 31, 2020, as the interest rate is variable and approximates prevailing market interest rates for similar debt arrangements. quoted market prices, based on estimated incremental borrowing rates for similar types of borrowing arrangements. PPP Loan Prior to the Company’s IPO, the Company received the proceeds from a loan on April 14, 2020 in the amount of approximately $6.0 million (the “PPP Loan”) from PNC Bank, as lender, pursuant to the PPP of the Coronavirus Aid, Relief, and Economic Security Act. The Company accounted for the PPP Loan as a financial liability in accordance with ASC Topic 470, Debt. Accordingly, the PPP Loan was recognized within long-term debt and current portion of long-term debt in the Company’s consolidated balance sheet and the related accrued interest was included within accrued liabilities in the Company’s consolidated balance sheet as of December 31, 2020. In June 2021, the Company received notice of forgiveness of the PPP Loan in whole, including all accrued unpaid interest. The Company recorded the forgiveness of approximately $6.0 million of principal and $0.1 million of accrued interest, which is included in gain on extinguishment of debt on the condensed consolidated statements of operations for the nine months ended September 30, 2021. Revolving Credit Facility On October 31, 2019, we entered into an asset-based revolving credit and security agreement with PNC Bank (the “Loan Agreement”). The Loan Agreement provides a senior secured revolving credit facility of up to $40.0 million with a maturity date of October 31, 2024. The Loan Agreement is collateralized by security interests in substantially all of our assets. Advances under the Loan Agreement bear interest through maturity at a variable rate based upon our selection of either a Domestic Rate or a LIBOR Rate, plus an applicable margin (“Domestic Rate Loans” and “LIBOR Rate Loans”). The Domestic Rate is defined as a fluctuating interest rate equal to the greater of (1) the base commercial lending rate of PNC Bank, (2) the overnight federal funds rate plus 0.50% and (3) the Daily LIBOR Rate plus 1.00%. The effective weighted average interest rate for the three and nine months ended September 30, 2021 was 3.61% and 3.61%, respectively. The applicable margin that commenced January 1, 2021 is between 1.50% to 2.25% for Domestic Rate Loans and between 3.50% and 4.25% for LIBOR Rate Loans based on maintaining certain undrawn availability ratios. For additional information regarding the applicable margin under the Loan Agreement, see Note 13 Subsequent Events. The Loan Agreement contains customary conditions to borrowings, events of default and covenants, including covenants that restrict our ability to sell assets, make changes to the nature of the business, engage in mergers or acquisitions, incur, assume or permit to exist additional indebtedness and guarantees, create or permit to exist liens, pay dividends, issue equity instruments, make distributions or redeem or repurchase capital stock or make other investments, and engage in transactions with affiliates. The Loan Agreement also requires that we maintain compliance with a minimum Fixed Charge Coverage Ratio (as defined in the Loan Agreement) of 1.40 to 1.00 at any time undrawn availability under the Loan Agreement is less than 25%. As of September 30, 2021, we are in compliance with all covenants.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	8. Stock-Based Compensation In connection with the IPO, which occurred on February 12, 2021, the Phantom Unit Plan was replaced by the 2021 LTIP. On February 12, 2021, 6.2 million RSUs were granted under the Company’s 2021 LTIP. The Company is authorized to grant RSUs, incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock awards, and performance stock awards under its 2021 LTIP. As of September 30, 2021, the Company has currently only granted RSUs and nonqualified stock options. Under the Company’s 2021 LTIP, 6.2 Stock-Based Compensation Stock-based compensation recorded in the condensed consolidated statements of operations was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) (in thousands) Platform operations $ 3,142 $ — $ 11,843 $ — Sales and marketing 4,859 — 23,586 — Technology and development 3,015 — 10,983 — General and administrative 4,399 — 15,780 — Total $ 15,415 $ — $ 62,192 $ — RSUs The following summarizes RSU activity: Number of Shares (in thousands) Weighted-Average Grant-Date Fair Value RSUs outstanding as of December 31, 2020 — $ — Granted 6,208 25.00 Vested — — Canceled/forfeited (26 ) 25.00 RSUs outstanding as of March 31, 2021 6,182 25.00 Granted 66 26.10 Vested — — Canceled/forfeited (64 ) 25.01 RSUs outstanding as of June 30, 2021 6,184 25.01 Granted 110 14.75 Vested (2,457 ) 24.86 Canceled/forfeited (452 ) 25.01 RSUs outstanding as of September 30, 2021 3,385 24.79 As of September 30, 2021, the Company had unrecognized stock-based compensation relating to RSUs of approximately $84.0 million, which is expected to be recognized over a weighted-average period of 2.4 Nonqualified Stock Options The following summarizes nonqualified stock option activity: Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (in thousands) (in years) (in thousands) Options outstanding as of December 31, 2020 — $ — Granted — — Exercised — — Canceled — — Expired — — Options outstanding as of March 31, 2021 — — Granted 67 26.09 Exercised — — Canceled — — Expired — — Options outstanding as of June 30, 2021 67 26.09 Granted 86 13.74 Exercised — — Canceled (6 ) 25.86 Expired — — Options outstanding as of September 30, 2021 147 18.91 9.8 $ 4 The weighted-average grant-date fair value of the nonqualified stock options granted during the three and nine months ended September 30, 2021 was $13.74 and $19.15, respectively. As of September 30, 2021, there were no nonqualified stock options vested or exercisable. T he Company had unrecognized stock-based compensation relating to unvested nonqualified stock options of approximately $ million, which is expected to be recognized over a weighted-average period of The following table presents the assumptions used in the Black-Scholes model to determine the fair value of nonqualified stock options for the three and nine months ended September 30, 2021. Black-Scholes assumptions have not been disclosed for any other periods presented as there were no nonqualified stock options granted in those periods. Three Months Ended September 30, Nine Months Ended September 30, 2021 2021 Risk free interest rate 1.2 % 1.2 % Expected volatility 61.1 % 61.1 % Expected term (in years) 5.9 5.9 Expected dividend yield 0.0 % 0.0 % Risk-Free Interest Rate. The Company bases the risk-free interest rate assumption for equity awards on the rates for U.S. Treasury securities with maturities similar to those of the expected term of the award being valued. Expected Volatility. Due to the limited trading history of the Company’s common stock, the expected volatility assumption is based on volatilities of a peer group of similar companies whose share prices are publicly available. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of the Company’s own stock price becomes available. Expected Term. Given the insufficient historical data relating to nonqualified stock option exercises, the expected term assumption is based on expected terms of a peer group of similar companies whose expected terms are publicly available. The Company will continue to apply this process until a sufficient amount of historical information regarding the Company’s nonqualified stock option exercises becomes available. Expected Dividend Yield. The Company’s expected dividend yield assumption is zero as it has never paid dividends and has no present intention to do so in the future. Issuance of Shares Upon vesting of shares under the LTIP, we will issue treasury stock. If treasury stock is not available, Class A common stock will be issued.

Income Taxes and Tax Receivable

Income Taxes and Tax Receivable Agreement	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes and Tax Receivable Agreement	9. Income Taxes and Tax Receivable Agreement The provision for income taxes differs from the amount of income tax computed by applying the applicable U.S. statutory federal income tax rate of 21% to income before provision of income taxes due to Viant Technology LLC’s pass-through structure for U.S. income tax purposes, pass-through permanent differences related to forgiveness of the PPP Loan and the valuation allowance against the deferred tax asset. The Company did not recognize an income tax expense/(benefit) on its share of pre-tax book income (loss), exclusive of the noncontrolling interest of 77.8% due to the full valuation allowance against its deferred tax assets, resulting in an effective tax rate of 0.0% for the three and nine months ended September 30, 2021. As of September 30, 2021, management determined based on applicable accounting standards and the weight of all available evidence, it was not more likely than not (“MLTN”) that the Company will generate sufficient taxable income to realize our deferred tax assets including the difference in our tax basis in excess of the financial reporting value for our investment in Viant Technology LLC. Consequently, we have established a full valuation allowance against our deferred tax assets as of September 30, 2021. In the event that management subsequently determines that it is MLTN that we will realize our deferred tax assets in the future over the recorded amount, a decrease to the valuation allowance will be made, which will reduce the provision for income taxes. The Company has concluded based on applicable accounting standards and the weight of all available evidence, that it was MLTN that its deferred tax assets subject to the TRA would not be realized as of September 30, 2021. Therefore, the Company has not recorded a liability related to the remaining tax savings it may realize from utilization of such deferred tax assets after concluding it was not probable that such TRA liability would be paid based on its estimates of future taxable income. The total unrecorded TRA liability increased from $9.1 million for the six months ended June 30, 2021, to $10.2 million for the nine months ended September 30, 2021. The increase was driven by exchanges of Class B units for shares of Class A common stock of the Company during the three months ended September 30, 2021. For additional information regarding the exchanges of Class B units for Class A common stock, see Note 11 —

Earnings (Loss) Per Share_Unit

Earnings (Loss) Per Share/Unit	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Earnings (Loss) Per Share/Unit	1 0. Earnings (Loss) Per Share/Unit Prior to the Reorganization Transactions that occurred on February 12, 2021, the Viant Technology LLC membership structure included certain convertible preferred units and common units. As a result of the Reorganization Transactions, Class B units of Viant Technology LLC are exchangeable in the future for Class A common stock of the Company. As the conversion of Viant Technology LLC preferred and common units to Class B units was not done in a proportionate manner with respect to the rights and economic interests of the former Viant Technology LLC unit holders compared to those of the new Class B unit/shareholders in Viant Technology LLC and Viant Technology Inc., we do not believe it is appropriate to retrospectively adjust these units. Accordingly, the earnings per unit calculation presented for the three and nine months ended September 30, 2020 reflects units of the membership structure prior to the Reorganization Transactions. For the three and nine months ended September 30, 2021, basic net loss per share has been calculated by dividing net loss attributable to Class A common stockholders for the period subsequent to the Reorganization Transactions, by the weighted average number of shares of Class A common stock outstanding for the same period. Shares of Class A common stock are weighted for the portion of the period in which the shares were outstanding. Diluted net loss per share has been calculated in a manner consistent with that of basic net loss per share while considering all potentially dilutive shares of Class A common stock outstanding during the period. For the three and nine mon ths ended September 30 , 2020, basic earnings (loss) per unit represents net income (loss) divided by the weighted-average number of units outstanding. Diluted net income ( loss ) per share has been computed in a manner consistent with that of basic net loss per share while considering all shares of potentially dilutive common units that were outstanding during the period , inclusive of the convertible preferred units using the if-converted method and the incentive common units using the treasury stock method, if dilutive. For the three and nine mon ths ended September 30 , 2020 , there were no potential dilutive units related to incentive common units as they were all issued as of the beginning of the year. The undistributed earnings for the three and nine months ended September 30, 2020 have been allocated based on the participation rights of the convertible preferred and common units as if the earnings for the period have been distributed. As the participation in distributed and undistributed earnings is identical for both classes, the distributed and undistributed earnings are allocated on a proportionate basis. The following table presents the calculation of basic and diluted net earnings (loss) per share/unit for the three and nine months ended September 30, 2021, the period following the Reorganization Transactions, and for the three and nine months ended September 30, 2020. See Note 2 for additional information related to basic and diluted net loss per share/unit. Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands, except per share/unit data) (in thousands, except per share/unit data) Numerator Net income (loss) $ (12,160 ) $ 7,478 $ (45,127 ) $ 7,777 Less: Net loss attributable to noncontrolling interests (9,623 ) — (35,829 ) — Less: Undistributed earnings attributable to participating securities — (4,487 ) — (4,666 ) Net income (loss) attributable to Viant Technology Inc./common unitholders $ (2,537 ) $ 2,991 $ (9,298 ) $ 3,111 Denominator Weighted-average shares of Class A common stock/units outstanding—basic 12,489 400 11,894 400 Convertible preferred units — 600 — 600 Weighted-average shares of Class A common stock/units outstanding—diluted 12,489 1,000 11,894 1,000 Earnings (loss) per share of Class A common stock/unit—basic $ (0.20 ) $ 7.48 $ (0.78 ) $ 7.78 Earnings (loss) per share of Class A common stock/unit—diluted $ (0.20 ) $ 7.48 $ (0.78 ) $ 7.78 Anti-dilutive shares/units excluded from earnings (loss) per share of Class A common stock/unit—diluted: Restricted stock units 3,385 — 3,385 — Non-qualified stock options 147 — 147 — Shares of Class B common stock 47,137 — 47,137 — Total shares excluded from earnings (loss) per share of Class A common stock/unit—diluted 50,669 — 50,669 —

Noncontrolling Interests

Noncontrolling Interests	9 Months Ended
	Sep. 30, 2021
Noncontrolling Interest [Abstract]
Noncontrolling Interests	11. Noncontrolling Interests We are the sole managing member of Viant Technology LLC and, as a result, consolidate the financial results of Viant Technology LLC. We report noncontrolling interests representing the economic interests in Viant Technology LLC held by the other members of Viant Technology LLC. The Viant Technology LLC Agreement classifies the interests acquired by the Company as Class A units, reclassified the interests held by the continuing members of Viant Technology LLC as Class B units and permits the continuing members of Viant Technology LLC to exchange Class B units for shares of Class A common stock on a one-for-one basis or, at the election of Viant Technology Inc., for cash at the current fair value on the date of the exchange. The following table summarizes the ownership of Viant Technology LLC: As of September 30, 2021 As of February 12, 2021 Owner Units Owned Ownership Percentage Units Owned Ownership Percentage Viant Technology Inc. 13,482,550 22.2 % 11,500,000 19.5 % Noncontrolling interests 47,137,130 77.8 % 47,435,559 80.5 % Total 60,619,680 100.0 % 58,935,559 100.0 % During the three and nine months ended September 30, 2021, noncontrolling interests exchanged 0.3 million Class B units of Viant Technology, LLC for 0.3 million shares of the Company’s Class A common stock, which also resulted in the cancellation of 0.3 million shares of the Company’s Class B common stock that was previously held by noncontrolling interests with no additional consideration provided. The following table presents the effect of changes in the Company’s ownership interest in Viant Technology LLC on the Company’s equity for the periods indicated: Three Months Ended September 30, 2021 Nine Months Ended September 30, 2021 (in thousands) (in thousands) Net loss attributable to Viant Technology Inc. $ (2,537 ) $ (9,298 ) Transfers to noncontrolling interests: Decrease in the additional-paid-in-capital of Viant Technology Inc. as a result in ownership changes in Viant Technology LLC (40,427 ) (40,427 ) Net decrease in equity of Viant Technology Inc. due to equity interest transactions with noncontrolling interests $ (42,964 ) $ (49,725 )

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. Commitments Lease Commitments The Company conducts its operations in 10 office spaces around the United States that are under operating leases that expire over the next ten years. Rent expense is included in other current liabilities. The non-current portion of deferred rent of $ 0.6 million and $ 0.5 million as of September 30 , 2021 and December 31, 2020, respectively, is included in other long-term liabilities . Future operating As of September 30, 2021 Year (in thousands) Remainder of 2021 1,032 2022 2,923 2023 3,953 2024 3,060 2025 and thereafter 19,705 Total minimum payments $ 30,673 Legal Matters From Guarantees and Indemnities The Company has made condensed

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events In October 2021, the Company entered into an agreement with PNC Bank to amend the Loan Agreement, effective October 15, 2021. This amendment decreased the applicable margin to a range of 0.75% to 1.25%, replacing the previous applicable margin range of 1.50% to 2.25% for Domestic Rate Loans, and decreased the applicable margin to a range of 1.75% to 2.25%, replacing the previous applicable margin range of 3.50% to 4.25% for LIBOR Rate Loans, based on maintaining certain undrawn availability ratios.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Basis Of Presentation And Summary Of Significant Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation The condensed consolidated financial statements for interim financial information which are unaudited Viant Technology LLC is considered a variable interest entity, or VIE. The Company is the primary beneficiary and sole managing member of Viant Technology LLC and has decision making authority that significantly affects the economic performance of the entity. As a result, the Company consolidates Viant Technology LLC. All intercompany balances and transactions have been eliminated in consolidation Viant Technology LLC has been determined to be the predecessor for accounting purposes and, accordingly, the condensed consolidated financial statements for periods prior to the IPO and the related organizational transactions have been adjusted to combine the previously separate entities for presentation purposes. Amounts for the period from January 1, 2020 through February 11, 2021 presented in the condensed consolidated financial statements and notes to condensed consolidated financial statements herein represent the historical operations of Viant Technology LLC. The amounts as of September 30, 2021 and for the period from February 12, 2021 reflect the consolidated operations of the Company. Management believes that the accompanying condensed consolidated financial statements reflect the adjustments necessary for the fair statement of its condensed consolidated balance sheet as of September 30, 2021, results of operations for the three and nine months ended September 30, 2021 and 2020, and cash flows for the nine months ended September 30, 2021 and 2020. The condensed consolidated balance sheet as of December 31, 2020 was derived from the audited annual financial statements but does not contain all of the footnote disclosures from the annual financial statements. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with GAAP have been omitted. Accordingly, these condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and related notes included in its Annual Report on Form 10-K for the year ended December 31, 2020. The condensed consolidated results of operations for the three and nine months ended September 30, 2021 are not necessarily indicative of the results to be expected for the year ending December 31, 2021, or for any other future annual or interim period.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. On an on-going basis, management evaluates its estimates, primarily those related to revenue recognition, stock-based compensation, income taxes, allowances for doubtful accounts, the useful lives of capitalized software development costs and other property, equipment and software and assumptions used in the impairment analyses of long-lived assets and goodwill. These estimates are based on historical data and experience, as well as various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying amount of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. As of September 30, 2021, the impact of the COVID-19 pandemic on our business continues to evolve. As a result, many of our estimates and assumptions consider macro-economic factors in the market, which require increased judgment and carry a higher degree of variability and volatility. As events continue to evolve and additional information becomes available, our estimates may change materially in future periods.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Financial instruments consist of cash, accounts receivable, accounts payable, accrued liabilities and debt. The carrying amounts of the Company’s current financial assets and current financial liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation relates to equity awards granted under the Company’s 2021 LTIP, which is measured and recognized in the condensed consolidated financial statements based on the fair value of the equity awards granted. Since inception of the 2021 LTIP, the Company has only granted restricted stock units (“RSUs”) and nonqualified stock options. The fair value of RSUs is calculated using the closing market price of the Company’s common stock on the date of grant. The fair value of non-qualified stock options is estimated using the Black Scholes option pricing model. The Black Scholes option pricing model is impacted by the fair value of the Company’s common stock, as well as changes in certain assumptions, including but not limited to, the expected common stock price volatility over the term of the nonqualified stock options, the expected term of the nonqualified stock options, the risk-free interest rate, and the expected dividend yield. A portion of RSUs granted as of September 30, 2021 to certain employees and board members, pursuant to the 2021 LTIP, vested upon expiration of the 180 day IPO lock-up period during the three months ended September 30, 2021. The remainder of employee granted RSUs and nonqualified stock options will vest through the applicable vesting dates, subject to continued employment for employee grants. RSUs awarded to board members upon their appointment will vest on the third anniversary of the grant date and RSUs awarded to board members annually will vest on the first anniversary of the grant date.
Comprehensive Income (Loss)	Comprehensive Income (Loss) For the periods presented, net income (loss) is equal to comprehensive income (loss).
Noncontrolling Interests	Noncontrolling Interests The noncontrolling interests represent the economic interests of Viant Technology LLC held by Class B common stockholders. Income or loss is attributed to the noncontrolling interests based on the weighted average LLC interests outstanding during the period. The noncontrolling interests’ ownership percentage can fluctuate over time as Class A common shares are issued in connection with the 2021 LTIP or as the Class B common stockholders elect to exchange their Class B common stock (and corresponding Class B units of Viant Technology LLC) for Class A common stock.
Earnings (Loss) Per Share	Earnings (Loss) Basic number of The Company’s RSUs, nonqualified stock options and shares of Class B common stock do not share in the earnings or losses of the Company and are therefore not participating securities. As such, separate presentation of basic and diluted earnings (loss) per share of RSUs, nonqualified stock options and Class B common stock under the two-class method has not been presented. Diluted have an anti-dilutive effect. Shares of our Class B common stock , RSUs , and nonqualified stock options are considered potentially dilutive shares of Class A common stock; however, related amounts have been excluded from the computation of diluted earnings (loss) per share of Class A common stock because the effect would have been anti-dilutive under the if-converted method.
Earnings (Loss) Per Unit	Earnings (Loss) Per Unit Basic earnings (loss) per unit is calculated by dividing the earnings (loss) attributable to common unitholders by the number of weighted-average common units outstanding. The Company applies the two-class method to allocate earnings between common and convertible preferred units. Diluted earnings (loss) per unit adjusts the basic earnings (loss) per unit attributable to common unitholders and the weighted-average number of units of common units outstanding for the potential dilutive impact of common units, using the treasury-stock method, and convertible preferred units using the if-converted method. Diluted earnings (loss) per unit considers the impact of potentially dilutive securities except in periods in which there is a loss because the inclusion of the potential common units would have an anti-dilutive effect.
Accounts Receivable, Net of Allowances	Accounts Receivable, The following (in thousands) Balance as of December 31, 2020 $ 335 Recovery of doubtful accounts (194 ) Write-offs, net of recoveries (126 ) Balance as of March 31, 2021 $ 15 Recovery of doubtful accounts (6 ) Write-offs, net of recoveries (1 ) Balance as of June 30, 2021 $ 8 Provision for doubtful accounts 39 Write-offs, net of recoveries (23 ) Balance as of September 30, 2021 $ 24
Deferred Offering Costs	Deferred Deferred $2.2 million . Upon of $4.3 million
Concentration of Risk	Concentration Financial ’s As of September 30, 2021, no individual customers accounted for more than 10% of consolidated accounts receivable. As of December 31, 2020, one individual customer accounted for 13.7% of consolidated accounts receivable. The following table provides the Company’s concentrations of credit risk with respect to individual customers as a percentage of the Company’s total revenues: Three Months Ended September 30, Nine Months Ended September 30, Individual Customer 2021 2020 2021 2020 A * 10.4 % * * * Less than 10% of total revenues. The following table provides the Company’s concentrations of credit risk with respect to advertising agency holding companies as a percentage of the Company’s total revenues: Three Months Ended September 30, Nine Months Ended September 30, Advertising Agency Holding Company 2021 2020 2021 2020 A * 12.2 % 11.8 % 10.3 % B 16.3 % * 10.2 % 10.4 % C * 14.6 % * 14.8 % * Less than 10% of total revenues. As of September 30, 2021, one individual supplier accounted for 16.5% of consolidated accounts payable and accrued liabilities. As of December 31, 2020, three suppliers accounted for 15.5%, 11.5%, and 10.9% of consolidated accounts payable and accrued liabilities, respectively.
Income Taxes	Income The Company is the managing member of Viant Technology LLC and, as a result, consolidates the financial results of Viant Technology LLC in the unaudited condensed consolidated financial statements. Viant Technology LLC is a pass-through entity for U.S. federal and most applicable state and local income tax purposes following a corporate reorganization effected in connection with our IPO. As an entity classified as a partnership for tax purposes, Viant Technology LLC is not subject to U.S. federal and certain state and local income taxes. Any taxable income or loss generated by Viant Technology LLC is passed through to, and included in the taxable income or loss of its members, including us. The Company is taxed as a corporation and pays corporate federal, state and local taxes with respect to income allocated from Viant Technology LLC, based on Viant Technology Inc.'s 22.2% economic interest in Viant Technology LLC as of September 30, 2021. The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities (“DTAs” and “DTLs”) for the expected future tax consequences of events that have been included in the financial statements. Under this method, we determine DTAs and DTLs on the basis of the differences between the financial statement and tax bases of assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on DTAs and DTLs is recognized in income in the period that includes the enactment date. We recognize DTAs to the extent that we believe that these assets are more likely than not to be realized. In making such a determination, we consider all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, carryback potential if permitted under the tax law, and results of recent operations. If we determine that we would be able to realize our DTAs in the future in excess of their net recorded amount, we would make an adjustment to the DTA valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions in accordance with ASC 740 on the basis of a two-step process in which (1) we determine whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, we recognize the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority.
Tax Receivable Agreement	Tax Receivable Agreement The Company expects to obtain an increase in its share of tax basis in the net assets of Viant Technology LLC when Class B units are exchanged by the holders of Class B units for shares of Class A common stock of the Company and upon other qualifying transactions. Each change in outstanding shares of Class A common stock of the Company results in a corresponding increase or decrease in the Company's ownership of Class A units of Viant Technology LLC. The Company intends to treat any exchanges of Class B units as direct purchases of LLC interests for U.S. federal income tax purposes. These increases in tax basis may reduce the amounts that the Company would otherwise pay in the future to various taxing authorities. They may also decrease gains (or increase losses) on future dispositions of certain capital assets to the extent tax basis is allocated to those capital assets. In connection with the IPO, the Company entered into a Tax Receivable Agreement (“TRA”) with Viant Technology LLC and the holders of Class B units of Viant Technology LLC (the “Members”). In the event that such parties exchange any or all of their Class B units for Class A common stock, the TRA requires the Company to make payments to such holders for 85% of the tax benefits realized, or in some cases deemed to be realized, by the Company by such exchange as a result of (i) increases in the Company’s tax basis of its ownership interest in the net assets of Viant Technology LLC resulting from any redemptions or exchanges of noncontrolling interest, (ii) tax basis increases attributable to payments made under the TRA, and (iii) deductions attributable to imputed interest pursuant to the TRA (the “TRA Payments”). The annual tax benefits are computed by calculating the income taxes due, including such tax benefits, and the income taxes due without such benefits. The Company expects to benefit from the remaining 15 % of any tax benefits that it may actually realize. The TRA Payments are not conditioned upon any continued ownership interest in Viant Technology LLC or the Company. To the extent that the Company is unable to timely make payments under the TRA for any reason, such payments generally will be deferred and will accrue interest until paid. The TRA provides that if (i) certain mergers, asset sales, other forms of business combinations, or other changes of control were to occur, (ii) there is a material breach of any material obligations under the TRA, or (iii) the Company elects an early termination of the TRA, then the TRA will terminate and the Company's obligations, or the Company's successor’s obligations, under the TRA will accelerate and become due and payable, based on certain assumptions, including an assumption that the Company would have sufficient taxable income to fully utilize all potential future tax benefits that are subject to the TRA and that any Class B units that have not been exchanged are deemed exchanged for the fair market value of the Company's Class A common stock at the time of termination
Treasury Stock	Treasury Stock We account for treasury stock under the cost method. When treasury stock
Recent Issued Accounting Pronouncements	Recent Issued On April The Company has elected condensed In February Financial Accounting Standards Board (“ Topic 842 will materially affect our consolidated balance sheet . We plan to adopt Topic 842 effective January 1, 202 2 and are currently evaluating the use of optional practical expedients. In June 2016, the condensed In October 2020, the FASB issued ASU No. 2020-10, Codification Improvements , The guidance is effective for the Company’s annual reporting period beginning after December 15, 2021 and interim reporting periods within the annual period beginning after December 15, 2022. The Company is currently assessing the impact this guidance will have on the condensed consolidated financial statements. In May 2021, the FASB issued ASU No. 2021-04, Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation—Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40). The purpose of ASU 2021-04 is to clarify and reduce diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options that remain equity classified after modification or exchange. The ASU requires issuers to account for modifications or exchanges of freestanding equity-classified written call options that remain equity classified after the modification or exchange based on the economic substance of the modification or exchange. In accordance with ASU 2021-04, an issuer determines the accounting for the modification or exchange based on whether the transaction was done to issue equity, to issue or modify debt, or for other reasons. The guidance is effective for the Company’s annual reporting period beginning after December 15, 2021 and interim reporting periods within that annual reporting period. The Company is currently assessing the impact this guidance will have on the condensed consolidated financial statements.
Recent Adopted Accounting Pronouncements	Recent Adopted In September prospectively In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes ("ASU 2019-12"). ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This guidance is effective for the Company’s annual reporting period beginning after December 15, 2020. The Company adopted ASU 2019-12 prospectively on January 1, 2021, and the adoption of this ASU did not have a material impact on the condensed consolidated financial statements.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Summary of Changes in Allowance for Doubtful Accounts	The following (in thousands) Balance as of December 31, 2020 $ 335 Recovery of doubtful accounts (194 ) Write-offs, net of recoveries (126 ) Balance as of March 31, 2021 $ 15 Recovery of doubtful accounts (6 ) Write-offs, net of recoveries (1 ) Balance as of June 30, 2021 $ 8 Provision for doubtful accounts 39 Write-offs, net of recoveries (23 ) Balance as of September 30, 2021 $ 24
Customer Concentration Risk
Schedules of Concentrations of Credit Risk	The following table provides the Company’s concentrations of credit risk with respect to individual customers as a percentage of the Company’s total revenues: Three Months Ended September 30, Nine Months Ended September 30, Individual Customer 2021 2020 2021 2020 A * 10.4 % * * * Less than 10% of total revenues.
Advertising Agency Risk
Schedules of Concentrations of Credit Risk	The following table provides the Company’s concentrations of credit risk with respect to advertising agency holding companies as a percentage of the Company’s total revenues: Three Months Ended September 30, Nine Months Ended September 30, Advertising Agency Holding Company 2021 2020 2021 2020 A * 12.2 % 11.8 % 10.3 % B 16.3 % * 10.2 % 10.4 % C * 14.6 % * 14.8 % * Less than 10% of total revenues.

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue From Contract With Customer [Abstract]
Summary of Disaggregation of Revenue	The disaggregation Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) (in thousands) Over-time revenue $ 1,136 $ 1,081 $ 3,344 $ 3,485 Point-in-time revenue 49,721 39,124 138,068 105,305 Total revenue $ 50,857 $ 40,205 $ 141,412 $ 108,790

Property, Equipment and Softw_2

Property, Equipment and Software, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Property Plant And Equipment [Abstract]
Schedule of Major Classes of Property, Equipment and Software	Major As of September 30, As of December 31, 2021 2020 (in thousands) Capitalized software development costs $ 59,156 $ 43,627 Computer equipment 1,827 1,575 Purchased software 32 32 Furniture, fixtures and office equipment 1,149 1,087 Leasehold improvements 2,161 2,115 Total property, equipment and software 64,325 48,436 Less: Accumulated depreciation (41,675 ) (34,607 ) Total property, equipment and software, net $ 22,650 $ 13,829
Schedule of Depreciation	Depreciation Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) (in thousands) Platform operations $ 2,080 $ 1,619 $ 5,424 $ 5,059 Sales and marketing — — — — Technology and development 421 403 1,185 1,206 General and administrative 164 171 494 468 Total $ 2,665 $ 2,193 $ 7,103 $ 6,733

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Balances of Intangibles Assets and Accumulated Amortization	The balances As of September 30, 2021 Remaining Weighted Average Useful Life Gross Amount Accumulated Amortization Net Carrying Amount (in years) (in thousands) Developed technology 1.3 $ 4,927 $ (3,994 ) $ 933 Customer relationships 2.3 2,300 (1,533 ) 767 Trademarks/tradenames 4.0 1,400 (1,007 ) 393 Total $ 8,627 $ (6,534 ) $ 2,093 As of December 31, 2020 Remaining Weighted Average Useful Life Gross Amount Accumulated Amortization Net Carrying Amount (in years) (in thousands) Developed technology 2.1 $ 4,927 $ (3,469 ) $ 1,458 Customer relationships 3.1 2,300 (1,287 ) 1,013 Trademarks/tradenames 4.2 1,400 (856 ) 544 Total $ 8,627 $ (5,612 ) $ 3,015
Summary of Amortization Recorded in Consolidated Statements of Operations	Amortization condensed Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) (in thousands) Platform operations $ 175 $ 175 $ 525 $ 525 Sales and marketing — — — — Technology and development — — — — General and administrative 132 132 396 396 Total $ 307 $ 307 $ 921 $ 921
Summary of Estimated Future Amortization of Intangible Assets	Estimated amortization As of September 30, 2021 Year (in thousands) Remainder of 2021 $ 308 2022 1,119 2023 467 2024 107 2025 80 Thereafter 12 Total $ 2,093

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Payables And Accruals [Abstract]
Summary of Accrued Liabilities	The Company’s As of September 30, As of December 31, 2021 2020 (in thousands) Accrued traffic acquisition costs $ 20,922 $ 22,667 Other accrued liabilities 2,318 2,010 Total accrued liabilities $ 23,240 $ 24,677

Long-Term Debt and Revolving _2

Long-Term Debt and Revolving Credit Facility (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of Debt and Revolving Credit Facilities	The Company’s As of September 30, As of December 31, 2021 2020 (in thousands) Revolving credit facility $ 17,500 $ 17,500 Paycheck Protection Program Loan — 6,035 Total debt 17,500 23,535 Less: Current portion of long-term debt — (3,353 ) Total long-term debt $ 17,500 $ 20,182

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock-based Compensation	Stock-based compensation recorded in the condensed consolidated statements of operations was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) (in thousands) Platform operations $ 3,142 $ — $ 11,843 $ — Sales and marketing 4,859 — 23,586 — Technology and development 3,015 — 10,983 — General and administrative 4,399 — 15,780 — Total $ 15,415 $ — $ 62,192 $ —
Summary of RSU Activity	The following summarizes RSU activity: Number of Shares (in thousands) Weighted-Average Grant-Date Fair Value RSUs outstanding as of December 31, 2020 — $ — Granted 6,208 25.00 Vested — — Canceled/forfeited (26 ) 25.00 RSUs outstanding as of March 31, 2021 6,182 25.00 Granted 66 26.10 Vested — — Canceled/forfeited (64 ) 25.01 RSUs outstanding as of June 30, 2021 6,184 25.01 Granted 110 14.75 Vested (2,457 ) 24.86 Canceled/forfeited (452 ) 25.01 RSUs outstanding as of September 30, 2021 3,385 24.79
Summary of Nonqualified Stock Option Activity	The following summarizes nonqualified stock option activity: Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value (in thousands) (in years) (in thousands) Options outstanding as of December 31, 2020 — $ — Granted — — Exercised — — Canceled — — Expired — — Options outstanding as of March 31, 2021 — — Granted 67 26.09 Exercised — — Canceled — — Expired — — Options outstanding as of June 30, 2021 67 26.09 Granted 86 13.74 Exercised — — Canceled (6 ) 25.86 Expired — — Options outstanding as of September 30, 2021 147 18.91 9.8 $ 4
Summary of Assumptions used in Black-Scholes Model to Determine Fair Value of Nonqualified Stock Options Granted	The following table presents the assumptions used in the Black-Scholes model to determine the fair value of nonqualified stock options for the three and nine months ended September 30, 2021. Black-Scholes assumptions have not been disclosed for any other periods presented as there were no nonqualified stock options granted in those periods. Three Months Ended September 30, Nine Months Ended September 30, 2021 2021 Risk free interest rate 1.2 % 1.2 % Expected volatility 61.1 % 61.1 % Expected term (in years) 5.9 5.9 Expected dividend yield 0.0 % 0.0 %

Earnings (Loss) Per Share_Unit

Earnings (Loss) Per Share/Unit (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Calculation of Basic and Diluted Net Earnings (Loss) Per Share/Unit	The following table presents the calculation of basic and diluted net earnings (loss) per share/unit for the three and nine months ended September 30, 2021, the period following the Reorganization Transactions, and for the three and nine months ended September 30, 2020. See Note 2 for additional information related to basic and diluted net loss per share/unit. Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands, except per share/unit data) (in thousands, except per share/unit data) Numerator Net income (loss) $ (12,160 ) $ 7,478 $ (45,127 ) $ 7,777 Less: Net loss attributable to noncontrolling interests (9,623 ) — (35,829 ) — Less: Undistributed earnings attributable to participating securities — (4,487 ) — (4,666 ) Net income (loss) attributable to Viant Technology Inc./common unitholders $ (2,537 ) $ 2,991 $ (9,298 ) $ 3,111 Denominator Weighted-average shares of Class A common stock/units outstanding—basic 12,489 400 11,894 400 Convertible preferred units — 600 — 600 Weighted-average shares of Class A common stock/units outstanding—diluted 12,489 1,000 11,894 1,000 Earnings (loss) per share of Class A common stock/unit—basic $ (0.20 ) $ 7.48 $ (0.78 ) $ 7.78 Earnings (loss) per share of Class A common stock/unit—diluted $ (0.20 ) $ 7.48 $ (0.78 ) $ 7.78 Anti-dilutive shares/units excluded from earnings (loss) per share of Class A common stock/unit—diluted: Restricted stock units 3,385 — 3,385 — Non-qualified stock options 147 — 147 — Shares of Class B common stock 47,137 — 47,137 — Total shares excluded from earnings (loss) per share of Class A common stock/unit—diluted 50,669 — 50,669 —

Noncontrolling Interests (Table

Noncontrolling Interests (Tables)	9 Months Ended
	Sep. 30, 2021
Noncontrolling Interest [Abstract]
Summary Ownership of Viant Technology LLC	The following table summarizes the ownership of Viant Technology LLC: As of September 30, 2021 As of February 12, 2021 Owner Units Owned Ownership Percentage Units Owned Ownership Percentage Viant Technology Inc. 13,482,550 22.2 % 11,500,000 19.5 % Noncontrolling interests 47,137,130 77.8 % 47,435,559 80.5 % Total 60,619,680 100.0 % 58,935,559 100.0 %
Summary of Effect of Changes in Ownership Interest in Viant Technology LLC on Equity	The following table presents the effect of changes in the Company’s ownership interest in Viant Technology LLC on the Company’s equity for the periods indicated: Three Months Ended September 30, 2021 Nine Months Ended September 30, 2021 (in thousands) (in thousands) Net loss attributable to Viant Technology Inc. $ (2,537 ) $ (9,298 ) Transfers to noncontrolling interests: Decrease in the additional-paid-in-capital of Viant Technology Inc. as a result in ownership changes in Viant Technology LLC (40,427 ) (40,427 ) Net decrease in equity of Viant Technology Inc. due to equity interest transactions with noncontrolling interests $ (42,964 ) $ (49,725 )

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Future Minimum Payments Under Non-cancelable Operating Leases	Future operating As of September 30, 2021 Year (in thousands) Remainder of 2021 1,032 2022 2,923 2023 3,953 2024 3,060 2025 and thereafter 19,705 Total minimum payments $ 30,673

Nature of Operations - Addition

Nature of Operations - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 12, 2021	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Nature Of Operations [Line Items]
Preferred stock, shares authorized	10,000,000	10,000,000	10,000,000
Common units, units outstanding		0	0	400,000
Proceeds from issuance of common stock, net of underwriting discounts			$ 232,500
Common stock, voting rights			The Class B stockholders and Class A stockholders initially had 80.5% and 19.5%, respectively, of the combined voting power of the Company’s common stock. The Class A common stock outstanding represents 100% of the rights of the holders of all classes of the Company’s outstanding common stock to share in distributions from the Company, except for the right of Class B stockholders to receive the par value of the Class B common stock upon our liquidation, dissolution or winding up or an exchange of Class B units
Underwriters
Nature Of Operations [Line Items]
Common stock shares issued and sold	10,000,000
Sale of stock, price per share	$ 25
Proceeds from issuance of common stock, net of underwriting discounts	$ 250,000
Payments of stock issuance costs	$ 17,500
Class A Common Stock
Nature Of Operations [Line Items]
Common stock, shares authorized	450,000,000	450,000,000	450,000,000
Common stock shares issued to continuing members		300,000	300,000
Underwrites options exercised shares issued	1,500,000
Common stock voting rights percentage	19.50%
Percentage of voting rights of outstanding common stock	100.00%
Class B Common Stock
Nature Of Operations [Line Items]
Common stock, shares authorized	150,000,000	150,000,000	150,000,000
Common stock shares issued to continuing members		(300,000)	(300,000)
Common stock voting rights percentage	80.50%
Class B Common Stock | Viant Technology LLC
Nature Of Operations [Line Items]
Common stock shares issued for each membership unit	1
Common stock shares issued to continuing members	48,935,559
Continuing Members Class B Units | Viant Technology LLC
Nature Of Operations [Line Items]
Continuing members units exchange description			one-for-one basis
Common units, units outstanding	48,935,559
Class A Units
Nature Of Operations [Line Items]
Members equity units received in exchange of units	1,500,000
Class A Units | Viant Technology LLC
Nature Of Operations [Line Items]
Payments to acquire units	$ 232,500
Member units acquired, units	10,000,000

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2021Supplier	Sep. 30, 2021CustomerSupplier	Dec. 31, 2020USD ($)CustomerSupplier	Feb. 28, 2021USD ($)
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Share-based compensation arrangement by share-based payment award, initial public offering lock-up period	180 days
Vesting, description		A portion of RSUs granted as of September 30, 2021 to certain employees and board members, pursuant to the 2021 LTIP, vested upon expiration of the 180 day IPO lock-up period during the three months ended September 30, 2021.  The remainder of employee granted RSUs and nonqualified stock options will vest through the applicable vesting dates, subject to continued employment for employee grants. RSUs awarded to board members upon their appointment will vest on the third anniversary of the grant date and RSUs awarded to board members annually will vest on the first anniversary of the grant date.
Tax receivable agreement required to make payments to shareholders realized percentage of tax benefits in event that exchange of units to shares		85.00%
Tax receivable agreement expected remaining tax benefit percentage		15.00%
ASU 2018-15
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021	Jan. 1, 2021
Change in accounting principle, accounting standards update, immaterial effect [true false]	true	true
ASU 2019-12
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021	Jan. 1, 2021
Change in accounting principle, accounting standards update, immaterial effect [true false]	true	true
SOFR
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Tax receivable agreement interest payments accrued basis spread rate		5.00%
Viant Technology LLC
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of economic interest held	22.20%	22.20%
Credit Concentration Risk | Accounts Receivable
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of customer | Customer		0	1
Concentration risk, percentage		10.00%
Credit Concentration Risk | Customer One | Accounts Receivable
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage			13.70%
Supplier Concentration Risk | Accounts Payable and Accrued Liabilities
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of supplier | Supplier	1	1	3
Supplier Concentration Risk | Accounts Payable and Accrued Liabilities | Supplier One
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage		16.50%	15.50%
Supplier Concentration Risk | Accounts Payable and Accrued Liabilities | Supplier Two
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage			11.50%
Supplier Concentration Risk | Accounts Payable and Accrued Liabilities | Supplier Three
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage			10.90%
IPO
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Deferred offering costs capitalized | $			$ 2.2	$ 4.3

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Changes in Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2021	Sep. 30, 2020
Basis Of Presentation And Summary Of Significant Accounting Policies [Abstract]
Beginning balance	$ 8	$ 15	$ 335	$ 335
Recovery of doubtful accounts	39	(6)	(194)	(161)	$ (236)
Write-offs, net of recoveries	(23)	(1)	(126)
Ending balance	$ 24	$ 8	$ 15	$ 24

Basis of Presentation and Sum_6

Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Concentrations of Credit Risk (Details) - Consolidated Revenue	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Customer Concentration Risk | Customer A
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage		10.40%
Advertising Agency Risk | Advertising Agency A
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage		12.20%	11.80%	10.30%
Advertising Agency Risk | Advertising Agency B
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	16.30%		10.20%	10.40%
Advertising Agency Risk | Advertising Agency C
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage		14.60%		14.80%

Basis of Presentation and Sum_7

Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Concentrations of Credit Risk (Parenthetical) (Details) - Consolidated Revenue - Maximum	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Customer Concentration Risk | Customer One
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	10.00%		10.00%	10.00%
Advertising Agency Risk | Advertising Agency A
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	10.00%
Advertising Agency Risk | Advertising Agency B
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage		10.00%
Advertising Agency Risk | Advertising Agency C
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	10.00%		10.00%

Revenue - Summary of Disaggrega

Revenue - Summary of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Revenue	$ 50,857	$ 40,205	$ 141,412	$ 108,790
Over-Time Revenue
Disaggregation Of Revenue [Line Items]
Revenue	1,136	1,081	3,344	3,485
Point-in-Time Revenue
Disaggregation Of Revenue [Line Items]
Revenue	$ 49,721	$ 39,124	$ 138,068	$ 105,305

Revenue - Additional Informatio

Revenue - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Contract with customer, liability, revenue recognized	$ 1.4
Expected Duration of Greater Than One Year
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation amount	6.9	$ 9.2
Expected to be Recognized within One Year
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation amount	$ 1.5	$ 3.6

Property, Equipment and Softw_3

Property, Equipment and Software, Net - Schedule of Major Classes of Property, Equipment and Software (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property, equipment and software	$ 64,325	$ 48,436
Less: Accumulated depreciation	(41,675)	(34,607)
Total property, equipment and software, net	22,650	13,829
Capitalized Software Development Costs
Property Plant And Equipment [Line Items]
Total property, equipment and software	59,156	43,627
Computer Equipment
Property Plant And Equipment [Line Items]
Total property, equipment and software	1,827	1,575
Purchased Software
Property Plant And Equipment [Line Items]
Total property, equipment and software	32	32
Furniture, Fixtures and Office Equipment
Property Plant And Equipment [Line Items]
Total property, equipment and software	1,149	1,087
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property, equipment and software	$ 2,161	$ 2,115

Property, Equipment and Softw_4

Property, Equipment and Software, Net - Schedule of Depreciation (Details) - USD ($) $ in Thousands	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	$ 2,665	$ 2,193	$ 7,103	$ 6,733
Platform Operations
Property Plant And Equipment [Line Items]
Depreciation	2,080	1,619	5,424	5,059
Technology and Development
Property Plant And Equipment [Line Items]
Depreciation	421	403	1,185	1,206
General and Administrative
Property Plant And Equipment [Line Items]
Depreciation	$ 164	$ 171	$ 494	$ 468

Property, Equipment and Softw_5

Property, Equipment and Software, Net - Additional Information (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 [Abstract]
Interest cost incurred	$ 0.2	$ 0.3	$ 0.7	$ 0.8

Intangible Assets, Net - Summar

Intangible Assets, Net - Summary of Balances of Intangibles Assets and Accumulated Amortization (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Finite Lived Intangible Assets [Line Items]
Gross Amount	$ 8,627	$ 8,627
Accumulated Amortization	(6,534)	(5,612)
Net Carrying Amount	$ 2,093	$ 3,015
Developed Technology
Finite Lived Intangible Assets [Line Items]
Remaining Weighted Average Useful Life	1 year 3 months 18 days	2 years 1 month 6 days
Gross Amount	$ 4,927	$ 4,927
Accumulated Amortization	(3,994)	(3,469)
Net Carrying Amount	$ 933	$ 1,458
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Remaining Weighted Average Useful Life	2 years 3 months 18 days	3 years 1 month 6 days
Gross Amount	$ 2,300	$ 2,300
Accumulated Amortization	(1,533)	(1,287)
Net Carrying Amount	$ 767	$ 1,013
Trademarks/Tradenames
Finite Lived Intangible Assets [Line Items]
Remaining Weighted Average Useful Life	4 years	4 years 2 months 12 days
Gross Amount	$ 1,400	$ 1,400
Accumulated Amortization	(1,007)	(856)
Net Carrying Amount	$ 393	$ 544

Intangible Assets, Net - Summ_2

Intangible Assets, Net - Summary of Amortization Recorded in Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Finite Lived Intangible Assets [Line Items]
Amortization	$ 307	$ 307	$ 921	$ 921
Platform Operations
Finite Lived Intangible Assets [Line Items]
Amortization	175	175	525	525
General and Administrative
Finite Lived Intangible Assets [Line Items]
Amortization	$ 132	$ 132	$ 396	$ 396

Intangible Assets, Net - Summ_3

Intangible Assets, Net - Summary of Estimated Future Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Remainder of 2021	$ 308
2022	1,119
2023	467
2024	107
2025	80
Thereafter	12
Net Carrying Amount	$ 2,093	$ 3,015

Accrued Liabilities - Summary o

Accrued Liabilities - Summary of Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued traffic acquisition costs	$ 20,922	$ 22,667
Other accrued liabilities	2,318	2,010
Total accrued liabilities	$ 23,240	$ 24,677

Long-Term Debt and Revolving _3

Long-Term Debt and Revolving Credit Facility - Schedule of Debt and Revolving Credit Facilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total debt	$ 17,500	$ 23,535
Less: Current portion of long-term debt		(3,353)
Total long-term debt	17,500	20,182
Revolving Credit Facility
Debt Instrument [Line Items]
Total debt	$ 17,500	17,500
Paycheck Protection Program Loan
Debt Instrument [Line Items]
Total debt		$ 6,035

Long-Term Debt and Revolving _4

Long-Term Debt and Revolving Credit Facility - Additional Information (Details) - USD ($)	Apr. 14, 2021	Oct. 31, 2019	Sep. 30, 2021	Sep. 30, 2021
Revolving Credit Facility | Loan Agreement | PNC Bank
Line Of Credit Facility [Line Items]
Senior secured revolving credit facility initiation date		Oct. 31, 2019
Senior secured revolving credit facility, maximum borrowing capacity		$ 40,000,000
Senior secured revolving credit facility maturity date		Oct. 31, 2024
Weighted average interest rate			3.61%	3.61%
Facility fee for undrawn amounts				0.375%
Line of credit facility, covenant terms				The Loan Agreement also requires that we maintain compliance with a minimum Fixed Charge Coverage Ratio (as defined in the Loan Agreement) of 1.40 to 1.00 at any time undrawn availability under the Loan Agreement is less than 25%.
Line of credit facility, covenant compliance				As of September 30, 2021, we are in compliance with all covenants
Revolving Credit Facility | Loan Agreement | PNC Bank | Domestic Rate Loans
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate plus margin				0.50%
Revolving Credit Facility | Loan Agreement | PNC Bank | Domestic Rate Loans | Minimum [Member]
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate plus margin				1.50%
Revolving Credit Facility | Loan Agreement | PNC Bank | Domestic Rate Loans | Maximum
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate plus margin				2.25%
Revolving Credit Facility | Loan Agreement | PNC Bank | LIBOR Rate Loans
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate plus margin				1.00%
Revolving Credit Facility | Loan Agreement | PNC Bank | LIBOR Rate Loans | Minimum [Member]
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate plus margin				3.50%
Revolving Credit Facility | Loan Agreement | PNC Bank | LIBOR Rate Loans | Maximum
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate plus margin				4.25%
Paycheck Protection Program Loan
Line Of Credit Facility [Line Items]
Proceeds from loan amount	$ 6,000,000
Paycheck Protection Program Loan | Principal Forgiveness
Line Of Credit Facility [Line Items]
Debt instrument forgiveness				$ 6,000,000
Paycheck Protection Program Loan | Accrued Interest Forgiveness
Line Of Credit Facility [Line Items]
Debt instrument forgiveness				$ 100,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 12, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield assumption		0.00%			0.00%
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based payment award equity instruments other than options grants in period		110,000	66,000	6,208,000
Unrecognized stock-based compensation expected to be recognized		$ 84			$ 84
Unrecognized stock-based compensation expected to be recognized over a weighted-average period					2 years 4 months 24 days
Nonqualified Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expected to be recognized		$ 1.5			$ 1.5
Unrecognized stock-based compensation expected to be recognized over a weighted-average period					3 years 9 months 18 days
Weighted-average grant-date fair value of stock options granted		$ 13.74			$ 19.15
Weighted-average grant-date stock options vested					0
Weighted-average grant-date stock options exercisable		0			0
2021 LTIP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares remained available for grant		6,200,000			6,200,000
2021 LTIP | Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based payment award equity instruments other than options grants in period	6,200,000

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-Based Compensation expense	$ 15,415	$ 62,192
Platform Operations
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-Based Compensation expense	3,142	11,843
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-Based Compensation expense	4,859	23,586
Technology and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-Based Compensation expense	3,015	10,983
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-Based Compensation expense	$ 4,399	$ 15,780

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of RSU Activity (Details) - Restricted Stock Units - $ / shares shares in Thousands	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs outstanding, beginning balance	6,184	6,182
Number of Shares, Granted	110	66	6,208
Number of Shares, Vested	2,457
Number of Shares, Canceled/forfeited	(452)	(64)	(26)
RSUs outstanding, ending balance	3,385	6,184	6,182
Number of Shares, Vested	(2,457)
Weighted-Average Grant-Date Fair Value of RSUs outstanding, beginning balance	$ 25.01	$ 25
Weighted-Average Grant-Date Fair Value of RSUs, Granted	14.75	26.10	$ 25
Weighted-Average Grant-Date Fair Value of RSUs, Vested	24.86
Weighted-Average Grant-Date Fair Value of RSUs, Canceled/forfeited	25.01	25.01	25
Weighted-Average Grant-Date Fair Value of RSUs outstanding, ending balance	$ 24.79	$ 25.01	$ 25

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Nonqualified Stock Option Activity (Details) - Nonqualified Stock Options - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options outstanding, beginning balance	67
Number of Options, Granted	86	67
Number of Options, Canceled	(6)
Number of Options outstanding, ending balance	147	67	147
Weighted-Average Exercise Price of Options outstanding, beginning balance	$ 26.09
Weighted-Average Exercise Price of Options, Granted	13.74	$ 26.09
Weighted-Average Exercise Price of Options, Canceled	25.86
Weighted-Average Exercise Price of Options outstanding, ending balance	$ 18.91	$ 26.09	$ 18.91
Canceled	6
Weighted-Average Remaining Contractual Term of Options outstanding			9 years 9 months 18 days
Aggregate Intrinsic Value of Options outstanding	$ 4		$ 4

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Assumptions used in Black-Scholes Model to Determine Fair Value of Nonqualified Stock Options Granted (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk free interest rate	1.20%	1.20%
Expected volatility	61.10%	61.10%
Expected term (in years)	5 years 10 months 24 days	5 years 10 months 24 days
Expected dividend yield	0.00%	0.00%

Income Taxes and Tax Receivab_2

Income Taxes and Tax Receivable Agreement - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2021
Income Tax Disclosure [Abstract]
U.S. statutory federal income tax rate			21.00%
Percentage of exclusive of non-controlling interest due to income tax expense/(benefit) not recognize on share of pre-tax book income (loss)			77.80%
Effective tax rate	0.00%		0.00%
TRA liability		$ 9.1	$ 10.2

Earnings (Loss) Per Share_Uni_2

Earnings (Loss) Per Share/Unit - Calculation of Basic and Diluted Net Earnings (Loss) Per Share/Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended					9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator
Net income (loss)	$ (12,160)	$ (18,095)	$ 7,478	$ (30)	$ 329	$ (45,127)	$ 7,777
Less: Net loss attributable to noncontrolling interests	(9,623)					(35,829)
Less: Undistributed earnings attributable to participating securities			(4,487)				(4,666)
Net income (loss) attributable to Viant Technology Inc./common unitholders	$ (2,537)		$ 2,991			$ (9,298)	$ 3,111
Weighted-average Class A common stock/units outstanding:
Weighted-average shares of Class A common stock/units outstanding—basic	12,489		400			11,894	400
Convertible preferred units			600				600
Weighted-average shares of Class A common stock/units outstanding—diluted	12,489		1,000			11,894	1,000
Earnings (loss) per share of Class A common stock/unit—basic	$ (0.20)		$ 7.48			$ (0.78)	$ 7.78
Earnings (loss) per share of Class A common stock/unit—diluted	$ (0.20)		$ 7.48			$ (0.78)	$ 7.78
Anti-dilutive shares/units excluded from earnings (loss) per share of Class A common stock/unit—diluted:
Total shares excluded from earnings (loss) per share of Class A common stock/unit?diluted	50,669					50,669
Class A Common Stock
Weighted-average Class A common stock/units outstanding:
Weighted-average shares of Class A common stock/units outstanding—basic	12,489		400			11,894	400
Weighted-average shares of Class A common stock/units outstanding—diluted	12,489		1,000			11,894	1,000
Earnings (loss) per share of Class A common stock/unit—basic	$ (0.20)		$ 7.48			$ (0.78)	$ 7.78
Earnings (loss) per share of Class A common stock/unit—diluted	$ (0.20)		$ 7.48			$ (0.78)	$ 7.78
Class B Common Stock
Anti-dilutive shares/units excluded from earnings (loss) per share of Class A common stock/unit—diluted:
Total shares excluded from earnings (loss) per share of Class A common stock/unit?diluted	47,137					47,137
Restricted Stock Units
Anti-dilutive shares/units excluded from earnings (loss) per share of Class A common stock/unit—diluted:
Total shares excluded from earnings (loss) per share of Class A common stock/unit?diluted	3,385					3,385
Non-qualified Stock Options
Anti-dilutive shares/units excluded from earnings (loss) per share of Class A common stock/unit—diluted:
Total shares excluded from earnings (loss) per share of Class A common stock/unit?diluted	147					147

Noncontrolling Interests - Addi

Noncontrolling Interests - Additional Information (Details) - shares	Feb. 12, 2021	Sep. 30, 2021	Sep. 30, 2021
Minority Interest [Line Items]
Common stock, conversion basis			continuing members of Viant Technology LLC to exchange Class B units for shares of Class A common stock on a one-for-one basis
Class A Common Stock
Minority Interest [Line Items]
Exchange units for shares of common stock			1
Exchange (cancellation) of shares		300,000	300,000
Class B Units | Viant Technology LLC
Minority Interest [Line Items]
Exchange of noncontrolling interests, shares		300,000	300,000
Class B Common Stock
Minority Interest [Line Items]
Exchange (cancellation) of shares		(300,000)	(300,000)
Class B Common Stock | Viant Technology LLC
Minority Interest [Line Items]
Exchange (cancellation) of shares	48,935,559

Noncontrolling Interests - Summ

Noncontrolling Interests - Summary Ownership of Viant Technology LLC (Details) - Viant Technology LLC - shares	Feb. 12, 2021	Sep. 30, 2021
Minority Interest [Line Items]
Units Owned	58,935,559	60,619,680
Ownership Percentage	100.00%	100.00%
Viant Technology Inc.
Minority Interest [Line Items]
Units Owned	11,500,000	13,482,550
Ownership percentage by Viant Technology Inc.	19.50%	22.20%
Noncontrolling Interests
Minority Interest [Line Items]
Units Owned	47,435,559	47,137,130
Ownership percentage by non-controlling interests	80.50%	77.80%

Noncontrolling Interests - Su_2

Noncontrolling Interests - Summary of Effect of Changes in Ownership Interest in Viant Technology LLC on Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Noncontrolling Interest [Abstract]
Net loss attributable to Viant Technology Inc.	$ (2,537)	$ 7,478	$ (9,298)	$ 7,777
Transfers to noncontrolling interests:
Decrease in the additional-paid-in-capital of Viant Technology Inc. as a result in ownership changes in Viant Technology LLC	(40,427)		(40,427)
Net decrease in equity of Viant Technology Inc. due to equity interest transactions with noncontrolling interests	$ (42,964)		$ (49,725)

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Commitments And Contingencies [Line Items]
Operating lease, description			The Company conducts its operations in 10 office spaces around the United States that are under operating leases that expire over the next ten years.
Lease expiration period			10 years
Rent expense	$ 1,200,000	$ 1,000,000	$ 3,200,000	$ 3,100,000
Contractual obligation amount	0		0
Other Current Liabilities
Commitments And Contingencies [Line Items]
Current portion of deferred rent	200,000		200,000		$ 400,000
Other Long-Term Liabilities
Commitments And Contingencies [Line Items]
Noncurrent portion of deferred rent	$ 600,000		$ 600,000		$ 500,000

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Payments Under Non-cancelable Operating Leases (Details) $ in Thousands	Sep. 30, 2021USD ($)
Commitments And Contingencies Disclosure [Abstract]
Remainder of 2021	$ 1,032
2022	2,923
2023	3,953
2024	3,060
2025 and thereafter	19,705
Total minimum payments	$ 30,673

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Revolving Credit Facility - Loan Agreement - PNC Bank	1 Months Ended	9 Months Ended
	Oct. 31, 2021	Sep. 30, 2021
Domestic Rate Loans
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate plus margin		0.50%
Domestic Rate Loans | Minimum [Member]
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate plus margin		1.50%
Domestic Rate Loans | Maximum
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate plus margin		2.25%
LIBOR Rate Loans
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate plus margin		1.00%
LIBOR Rate Loans | Minimum [Member]
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate plus margin		3.50%
LIBOR Rate Loans | Maximum
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate plus margin		4.25%
Subsequent Event | Domestic Rate Loans | Minimum [Member]
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate plus margin	0.75%
Subsequent Event | Domestic Rate Loans | Maximum
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate plus margin	1.25%
Subsequent Event | LIBOR Rate Loans | Minimum [Member]
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate plus margin	1.75%
Subsequent Event | LIBOR Rate Loans | Maximum
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate plus margin	2.25%