Basic and Diluted Net Loss Per Share - Summary of Computation of Diluted Net Loss Per Share (Detail) - shares	6 Months Ended
	Jul. 31, 2021	Jul. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	67,706,176	270,229,995
Redeemable Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	0	192,469,995
Options to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	26,401,717	39,463,877
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	4,017,149	0
Unvested early exercised common stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	211,464	102,781
Common Stock and Preferred Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	37,075,846	38,193,342