Basic and Diluted Net Loss per Share - Antidilutive Securities (Details) - shares	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	62,809,839	262,337,147	222,205,064
Redeemable convertible preferred stock (on an as-converted basis)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	0	193,037,715	170,686,661
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	22,200,869	30,167,178	34,883,465
Unvested restricted common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	0	0	166,100
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	4,033,418	0	0
Unvested early exercised common stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	132,180	371,193	58,830
Redeemable convertible preferred stock warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	0	2,358,546	2,358,546
Common stock warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	35,549,024	36,402,515	14,051,462
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	894,348	0	0