Revenue from contracts with customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Total revenue, net	$ 1,371	$ 1,137	$ 3,083	$ 2,546
Revenue recognized over the time
Disaggregation of Revenue [Line Items]
Total revenue, net	1,296	1,099	2,957	2,484
Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Total revenue, net	75	38	126	62
QCaaS
Disaggregation of Revenue [Line Items]
Total revenue, net	1,176	961	2,560	2,083
Professional services
Disaggregation of Revenue [Line Items]
Total revenue, net	156	158	464	429
Other revenue
Disaggregation of Revenue [Line Items]
Total revenue, net	$ 39	$ 18	$ 59	$ 34