Net Loss Per Share Attributable to Common Stockholders - Anti-Dilutive Common Stock Equivalents Excluded from Computation of Diluted Net Loss Per Share (Details) - shares shares in Thousands	12 Months Ended
	Jan. 31, 2023	Jan. 31, 2022	Jan. 31, 2021
Class A Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	46,725	111,527	359,295
Class A Common Stock | Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	0	68,015	288,979
Class A Common Stock | Unvested RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	31,427	23,237	31,074
Class A Common Stock | Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	13,967	18,424	37,814
Class A Common Stock | Shares subject to repurchase from RSAs and early exercised stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	284	1,539	1,428
Class A Common Stock | Shares issuable under 2021 ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	828	312	0
Class A Common Stock | Returnable shares issued in connection with business acquisition
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	219	0	0
Class B Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	0	0	0
Class B Common Stock | Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	0	0	0
Class B Common Stock | Unvested RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	0	0	0
Class B Common Stock | Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	0	0	0
Class B Common Stock | Shares subject to repurchase from RSAs and early exercised stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	0	0	0
Class B Common Stock | Shares issuable under 2021 ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	0	0	0
Class B Common Stock | Returnable shares issued in connection with business acquisition
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total weighted-average anti-dilutive common stock equivalents	0	0	0