Equity Incentive Plans and Stock-Based Compensation - Additional Information (Details) - USD ($)		1 Months Ended			12 Months Ended
	Apr. 23, 2021	Apr. 22, 2021	Sep. 30, 2020	Jul. 31, 2020	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020	Apr. 30, 2021	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested options expiration period after termination of employment					3 months
Weighted-average grant date fair value of stock options granted (in dollars per share)					$ 45.78	$ 17.45	$ 3.76
Intrinsic value of stock options exercised					$ 557,500,000	$ 839,000,000	$ 92,700,000
Stock-based compensation expense					515,583,000	86,167,000	137,862,000
Cost not yet recognized for unvested options				$ 700,000	139,100,000
Fair value of RSUs vested					1,400,000,000	0	0
Restricted stock awards issued, value						373,000
Capitalized stock-based compensation expenses relating to software development cost					$ 4,500,000	$ 300,000	$ 400,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuances (in shares)		15,500,000
Period of shares automatically increase		10 years
Percentage of total number of shares		1.00%
Number of shares authorized (in shares)		10,500,000
Weighted-average remaining period for cost recognition					4 months 24 days
Unrecognized compensation expense					$ 4,000,000
Shares purchased (in shares)					400,000
Purchase price (in dollars per share)					$ 35.24
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					4 years
Award expiration period					10 years
Accelerated vesting shares (in shares)					200,000	300,000	100,000
Incremental expense				$ 1,600,000	$ 2,900,000	$ 4,600,000	$ 100,000
Awards modified (in shares)				4,600,000
Stock-based compensation expense				$ 900,000
Weighted-average remaining period for cost recognition					3 years 1 month 6 days
Early Exercised Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding underlying unvested stock options that had been early exercised (in shares)					800,000
Accrued proceeds from unvested early exercised stock options					$ 2,800,000	$ 5,900,000
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated vesting shares (in shares)					200,000		100,000
Incremental expense					$ 10,900,000		$ 800,000
Weighted-average remaining period for cost recognition					3 years 3 months 18 days
Expense acceleration					$ 2,200,000
Unrecognized compensation expense					$ 777,800,000
Grant date fair value per share (in dollars per share)					$ 45.09
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			4 years
Weighted-average remaining period for cost recognition					2 years 7 months 6 days
Unrecognized compensation expense					$ 2,600,000
Restricted stock awards issued (in shares)			100,000
Grant date fair value per share (in dollars per share)			$ 33.22
Restricted stock awards issued, value			$ 4,000,000
Class A Common Stock | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common stock, offering date, percent of market price		85.00%
Purchase price of common stock, purchase date, percent of market price		85.00%
2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of shares automatically increase		10 years
Percentage of total number of shares		5.00%
2021 Plan | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					4 years
2021 Plan | Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuances (in shares)		118,800,000
2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuances (in shares)									0
2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuances (in shares)								0
2018 Plan | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 233,000,000
Award service period					4 years