Consolidated Statements of Convertible Preferred Stock and Stockholders Equity (Deficit) - USD ($) shares in Thousands	Total	Convertible Preferred Stock	Class A Common Stock	Class B Common Stock	Common stock Class A Common Stock	Common stock Class B Common Stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated deficit
Beginning Balance (in shares) at Jan. 31, 2019		237,617
Beginning Balance at Jan. 31, 2019		$ 413,380,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock, net of issuance costs (in shares)		44,491
Issuance of convertible preferred stock, net of issuance costs		$ 583,009,000
Ending Balance (in shares) at Jan. 31, 2020		282,108
Ending Balance at Jan. 31, 2020		$ 996,389,000
Beginning Balance (in shares) at Jan. 31, 2019					27,468	120,913
Beginning Balance at Jan. 31, 2019	$ (297,943,000)				$ 0	$ 1,000	$ 22,620,000	$ 1,052,000	$ (321,616,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and vesting of restricted stock units (in shares)					19,066
Issuance of common stock upon exercise of stock options and restricted stock awards	3,774,000						3,774,000
Repurchase and retirement of common stock in connection with convertible preferred stock financing (in shares)					(4,651)	(5,172)
Repurchase and retirement of common stock in connection with convertible preferred stock financing	(64,959,000)						(28,541,000)		(36,418,000)
Stock-based compensation expense related to tender offer	48,260,000						48,260,000
Stock-based compensation expense	26,116,000						26,116,000
Other comprehensive income (loss), net of tax	5,174,000							5,174,000
Net loss	(519,933,000)		$ (120,959,000)	$ (398,974,000)					(519,933,000)
Ending Balance (in shares) at Jan. 31, 2020					41,883	115,741
Ending Balance at Jan. 31, 2020	$ (799,511,000)				$ 0	$ 1,000	72,229,000	6,226,000	(877,967,000)
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock, net of issuance costs (in shares)		12,149
Issuance of convertible preferred stock, net of issuance costs		$ 225,579,000
Ending Balance (in shares) at Jan. 31, 2021	294,257	294,257
Ending Balance at Jan. 31, 2021	$ 1,221,968,000	$ 1,221,968,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and vesting of restricted stock units (in shares)					28,196
Issuance of common stock upon exercise of stock options and restricted stock awards	20,519,000				$ 1,000		20,518,000
Issuance of common stock upon settlement/vesting of restricted stock/restricted stock units (in shares)					10
Issuance of common stock upon vesting of restricted stock awards	373,000						373,000
Stock-based compensation expense related to common stock secondary transactions (in shares)					5,088	(5,088)
Stock-based compensation expense related to common stock secondary transactions	4,983,000						4,983,000
Stock-based compensation expense	81,072,000						81,072,000
Other comprehensive income (loss), net of tax	(18,747,000)							(18,747,000)
Net loss	(92,393,000)		(29,243,000)	(63,150,000)					(92,393,000)
Ending Balance (in shares) at Jan. 31, 2021					75,177	110,653
Ending Balance at Jan. 31, 2021	(803,704,000)				$ 1,000	$ 1,000	179,175,000	(12,521,000)	(970,360,000)
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock, net of issuance costs (in shares)		12,043
Issuance of convertible preferred stock, net of issuance costs		$ 749,836,000
Conversion of convertible preferred stock to common stock upon initial public offering (in shares)		(306,300)			306,300
Conversion of convertible preferred stock to common stock upon initial public offering	$ 1,971,804,000	$ (1,971,804,000)			$ 3,000		1,971,801,000
Ending Balance (in shares) at Jan. 31, 2022	0	0
Ending Balance at Jan. 31, 2022	$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of convertible preferred stock to common stock upon initial public offering (in shares)		(306,300)			306,300
Conversion of convertible preferred stock to common stock upon initial public offering	1,971,804,000	$ (1,971,804,000)			$ 3,000		1,971,801,000
Issuance of common stock upon initial public offering, net of underwriting discounts and commissions and other issuance costs (in shares)					13,000
Issuance of common stock upon initial public offering, net of underwriting discounts and commissions and other issuance costs	687,903,000						687,903,000
Conversion of shares of Class B common stock into shares of Class A common stock (in shares)					28,200
Conversion of shares of Class B common stock into shares of Class A common stock						$ (28,200,000)
Shares issued as consideration for business acquisition (in shares)					543
Shares issued as consideration for business acquisition	$ 30,467,000						30,467,000
Issuance of common stock upon exercise of stock options (in shares)	10,048				10,048
Issuance of common stock upon exercise of stock options	$ 12,345,000						12,345,000
Vesting of early exercised stock options	3,017,000						3,017,000
Issuance of common stock under the employee stock purchase plan (in shares)					411
Issuance of common stock under the employee stock purchase plan	14,462,000						14,462,000
Issuance of common stock upon settlement/vesting of restricted stock/restricted stock units (in shares)					25,280
Tax withholdings on settlement of restricted stock units (in shares)					(186)
Tax withholdings on settlement of restricted stock units	(10,591,000)						(10,591,000)
Stock-based compensation expense	518,380,000						518,380,000
Other comprehensive income (loss), net of tax	23,420,000							23,420,000
Net loss	(525,586,000)		$ (423,296,000)	$ (102,290,000)					(525,586,000)
Ending Balance (in shares) at Jan. 31, 2022					458,773	82,453
Ending Balance at Jan. 31, 2022	$ 1,921,917,000				$ 4,000	$ 1,000	$ 3,406,959,000	$ 10,899,000	$ (1,495,946,000)