Net Loss Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2023
Numerator:
Net loss	$ (1,154,820)	$ (354,158)	$ (277,746)
Denominator:
Weighted-average common stock shares used in computing net loss per share, basic (in shares)	154,294	60,628	59,590
Weighted-average common stock shares used in computing net loss per share, diluted (in shares)	154,294	60,628	59,590
Net loss per common stock share, basic (in dollars per share)	$ (7.48)	$ (5.84)	$ (4.66)
Net loss per common stock share, diluted (in dollars per share)	$ (7.48)	$ (5.84)	$ (4.66)
Class A common stock
Numerator:
Net loss	$ 428,333
Denominator:
Weighted-average common stock shares used in computing net loss per share, basic (in shares)	57,229
Weighted-average common stock shares used in computing net loss per share, diluted (in shares)	57,229
Net loss per common stock share, basic (in dollars per share)	$ 7.48
Net loss per common stock share, diluted (in dollars per share)	$ 7.48
Class B common stock
Numerator:
Net loss	$ 726,487	$ (354,158)	$ (277,746)
Denominator:
Weighted-average common stock shares used in computing net loss per share, basic (in shares)	97,065	55,228	54,190
Weighted-average common stock shares used in computing net loss per share, diluted (in shares)	97,065	55,228	54,190
Net loss per common stock share, basic (in dollars per share)	$ 7.48	$ (5.84)	$ (4.66)
Net loss per common stock share, diluted (in dollars per share)	$ 7.48	$ (5.84)	$ (4.66)
Common Stock B, Founders Stock
Denominator:
Weighted-average common stock shares used in computing net loss per share, basic (in shares)		5,400	5,400
Weighted-average common stock shares used in computing net loss per share, diluted (in shares)		5,400	5,400
Net loss per common stock share, basic (in dollars per share)		$ (5.84)	$ (4.66)
Net loss per common stock share, diluted (in dollars per share)		$ (5.84)	$ (4.66)