Stock-based compensation - Stock Options - (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning balance (in shares)	8,800,464
Granted (in shares)	1,911,670
Exercised (in shares)	(27,613)
Cancelled or forfeited (in shares)	(162,438)
Outstanding, ending balance (in shares)	10,522,083	8,800,464
Exercisable (in shares)	5,065,944
Weighted Average Exercise Price
Outstanding (in dollars per share)	$ 8.1
Granted (in dollars per share)	4.27
Exercised (in dollars per share)	2.96
Cancelled or forfeited (in dollars per share)	7.41
Outstanding (in dollars per share)	7.43	$ 8.1
Exercisable (in dollars per share)	$ 8.41
Remaining Contractual Life
Outstanding	7 years 4 months 24 days	7 years 3 months 18 days
Exercisable	6 years 1 month 6 days
Aggregate Intrinsic Value
Outstanding	$ 499	$ 3,462
Exercisable	406
Employee Stock Option
Options disclosures
Unrecognized stock-based compensation expense	$ 20,500
Remaining weighted-average remaining vesting period	2 years 8 months 12 days