CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' (DEFICIT) EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive (Loss) Income	(Accumulated Deficit) Retained Earnings
Beginning balance (in shares) at Jan. 31, 2019	152,665,804
Beginning balance at Jan. 31, 2019	$ 159,552
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of convertible preferred stock to common stock upon initial public offering (in shares)	(152,665,804)
Issuance of common stock upon follow-on public offering, net of underwriting discounts and commissions and other offering costs	$ (159,552)
Ending balance (in shares) at Jan. 31, 2020	0
Ending balance at Jan. 31, 2020	$ 0
Beginning balance (in shares) at Jan. 31, 2019		90,327,435
Beginning balance at Jan. 31, 2019	(7,439)	$ 89	$ 17,760	$ (135)	$ (25,153)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of convertible preferred stock to common stock upon initial public offering (in shares)		152,665,804
Conversion of convertible preferred stock to common stock upon initial public offering	159,552	$ 153	159,399
Conversion of convertible promissory notes and accrued interest to common stock upon initial public offering (in shares)		426,223
Conversion of convertible promissory notes and accrued interest to common stock upon initial public offering	15,344		15,344
Issuance of common stock, net of underwriting discounts and commissions and other offering costs (in shares)		15,819,646
Issuance of common stock, net of underwriting discounts and commissions and other offering costs	541,499	$ 16	541,483
Issuance of common stock upon exercise of stock options, net of repurchases and release of restricted stock units (in shares)		18,501,767
Issuance of common stock upon exercise of stock options, net of repurchases and release of restricted stock units	9,771	$ 19	9,752
Issuance of common stock reserved for charitable donation (in shares)		500,000
Issuance of common stock for employee stock purchase plan (in shares)		490,268
Issuance of common stock for employee stock purchase plan	15,482		15,482
Stock-based compensation expense	73,485		73,485
Other comprehensive income	944			944
Net income	25,305				25,305
Ending balance (in shares) at Jan. 31, 2020		278,731,143
Ending balance at Jan. 31, 2020	$ 833,943	$ 277	832,705	809	152
Ending balance (in shares) at Jan. 31, 2021	0
Ending balance at Jan. 31, 2021	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		7,378,477
Issuance of common stock upon exercise of stock options	29,107	$ 7	29,100
Issuance of common stock, net of underwriting discounts and commissions and other offering costs (in shares)		5,882,353
Issuance of common stock, net of underwriting discounts and commissions and other offering costs	1,979,544	$ 6	1,979,538
Issuance of common stock upon release of restricted stock units (in shares)		633,697
Issuance of common stock upon release of restricted stock units	1	$ 1
Charitable donation of common stock	23,312		23,312
Issuance of common stock for employee stock purchase plan (in shares)		923,553
Issuance of common stock for employee stock purchase plan	38,433	$ 1	38,432
Stock-based compensation expense	284,081		284,081
Other comprehensive income	30			30
Net income	672,316				672,316
Ending balance (in shares) at Jan. 31, 2021		293,549,223
Ending balance at Jan. 31, 2021	$ 3,860,767	$ 292	3,187,168	839	672,468
Ending balance (in shares) at Jan. 31, 2022	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	2,881,485	2,881,485
Issuance of common stock upon exercise of stock options	$ 14,810	$ 4	14,806
Issuance of common stock upon release of restricted stock units (in shares)		1,768,702
Issuance of common stock upon release of restricted stock units	2	$ 2
Issuance of common stock for employee stock purchase plan (in shares)		838,395
Issuance of common stock for employee stock purchase plan	59,331	$ 1	59,330
Stock-based compensation expense	488,210		488,210
Other comprehensive income	(18,741)			(18,741)
Net income	1,375,639				1,375,639
Ending balance (in shares) at Jan. 31, 2022		299,037,805
Ending balance at Jan. 31, 2022	$ 5,780,018	$ 299	$ 3,749,514	$ (17,902)	$ 2,048,107