Net loss per share - Basic and diluted net loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Numerator:
Net loss	$ (180,664)	$ (112,717)	$ (66,819)
Denominator:
Weighted average ordinary shares outstanding, basic	35,592,362	29,660,659	25,061,734
Weighted average ordinary shares outstanding, diluted	35,592,362	29,660,659	25,061,734
Net loss per share, basic	$ (5.08)	$ (3.80)	$ (2.67)
Net loss per share, diluted	$ (5.08)	$ (3.80)	$ (2.67)