Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Summary of Restricted Stock Units Activity Under Equity Incentive Plan (Details) - RSUs	12 Months Ended
	Jan. 31, 2021 $ / shares shares
Unvested RSUs
Beginning balance (in units) | shares	1,964,668
Granted (in units) | shares	3,351,979
Vested (in units) | shares	(625,163)
Cancelled/forfeited (in units) | shares	(180,754)
Ending balance (in units) | shares	4,510,730
Weighted-Average Grant Date Fair Value Per Share
Beginning balance (in dollars per unit) | $ / shares	$ 79.11
Granted (in dollars per unit) | $ / shares	241.32
Vested (in dollars per unit) | $ / shares	86.29
Cancelled/forfeited (in dollars per unit) | $ / shares	181.18
Ending balance (in dollars per unit) | $ / shares	$ 194.57