Net Loss Per Share - Antidilutive Securities (Details) - shares	3 Months Ended
	Apr. 30, 2026	Apr. 30, 2025
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities (in shares)	56,706,271	218,013,884
Redeemable convertible preferred shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities (in shares)	0	146,360,207
Stock options issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities (in shares)	37,455,860	42,312,726
RSUs issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities (in shares)	18,806,310	7,150,664
Employee Stock Purchase Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities (in shares)	440,790	0
Warrants to purchase redeemable convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities (in shares)	0	40,160
Warrants to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities (in shares)	0	1,216,176
Shares of common stock subject to repurchase
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities (in shares)	3,311	36,180
Convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities (in shares)	0	12,948,711
SAFE Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities (in shares)	0	7,949,060