Net loss per share attributable to common stockholders - Schedule of Shares Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended
	Apr. 30, 2024	Apr. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	6,480,070	7,505,338
Stock options to purchase common stock, restricted stock and performance stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	6,390,517	7,428,704
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	89,553	76,634