Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Net revenue	$ 676,171	$ 748,206	$ 517,175
Costs of revenue	346,657	428,205	285,470
Gross profit	329,514	320,001	231,705
Operating expenses:
Compensation and benefits	499,595	415,094	318,116
Technology	55,612	52,361	33,637
Professional services	21,679	23,479	18,443
Occupancy	4,361	4,514	4,181
Depreciation and amortization	10,741	3,853	3,534
Marketing and advertising	2,566	3,995	2,284
Other operating expenses	17,975	26,513	13,516
Total operating expenses	612,529	529,809	393,711
Loss from operations	(283,015)	(209,808)	(162,006)
Other income (expense), net	52,440	24,926	(2,563)
Loss before income tax expense	(230,575)	(184,882)	(164,569)
Income tax benefit	(7,613)	(102)	(640)
Net loss	(222,962)	(184,780)	(163,929)
Net loss attributable to common stockholders, basic	(222,962)	(184,780)	(163,929)
Net loss attributable to common stockholders, diluted	(222,962)	(184,780)	(163,929)
Other comprehensive income (loss), net of taxes:
Change in foreign currency translation adjustment	(40)	(167)	(14)
Net change in unrealized gain (loss) on short-term investments	8,039	(4,840)	(2,241)
Net other comprehensive income (loss)	7,999	(5,007)	(2,255)
Comprehensive loss	$ (214,963)	$ (189,787)	$ (166,184)
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (0.42)	$ (0.34)	$ (0.45)
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (0.42)	$ (0.34)	$ (0.45)
Weighted-average shares used in computing net loss per share attributable to common stockholders - basic (in shares)	532,540,175	545,397,254	362,756,466
Weighted-average shares used in computing net loss per share attributable to common stockholders - diluted (in shares)	532,540,175	545,397,254	362,756,466