Net Loss Per Share Attributable to Common Stockholders - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss	$ (525,586)	$ (92,393)	$ (519,933)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic (in shares)	454,625	168,255	152,382
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (1.16)	$ (0.55)	$ (3.41)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, diluted (in shares)	454,625	168,255	152,382
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (1.16)	$ (0.55)	$ (3.41)
Class A Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss	$ (423,296)	$ (29,243)	$ (120,959)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic (in shares)	366,146	53,253	35,450
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (1.16)	$ (0.55)	$ (3.41)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, diluted (in shares)	366,146	53,253	35,450
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (1.16)	$ (0.55)	$ (3.41)
Class B Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss	$ (102,290)	$ (63,150)	$ (398,974)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic (in shares)	88,479	115,002	116,932
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (1.16)	$ (0.55)	$ (3.41)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, diluted (in shares)	88,479	115,002	116,932
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (1.16)	$ (0.55)	$ (3.41)