Revenue from contracts with customers (Tables)

9 Months Ended

Sep. 30, 2023

Revenue from Contract with Customer [Abstract]

Disaggregation of revenue

The following table depicts the disaggregation of revenue by type of products or services and timing of transfer of products or services (in thousands):

	Three months ended September 30,
	2023		2022
Type of products or services
QCaaS	$	1,132	$	1,346
Professional services	1,421		347
Other revenue	9		2
Total revenue	$	2,562	$	1,695
Timing of revenue recognition
Revenue recognized over time	$	2,506	$	1,660
Revenue recognized at a point in time	56		35
Total revenue	$	2,562	$	1,695

	Nine months ended September 30,
	2023		2022
Type of products or services
QCaaS	$	3,333	$	3,905
Professional services	2,482		812
Other revenue	37		61
Total revenue	$	5,852	$	4,778
Timing of revenue recognition
Revenue recognized over time	$	5,713	$	4,618
Revenue recognized at a point in time	139		160
Total revenue	$	5,852	$	4,778

The following tables present a summary of revenue by geography, based on the addresses of our customers, for the three and nine months ended September 30, 2023 and 2022 (in thousands):

	Three months ended September 30,
	2023		2022
United States	$	1,083	$	951
Japan	299		293
Germany	287		237
Switzerland	311		—
Other	582		214
Total revenue	$	2,562	$	1,695

	Nine Months Ended September 30,
	2023		2022
United States	$	1,814	$	2,461
Japan	920		1,008
Germany	865		757
Switzerland	686		—
Other	1,567		552
Total revenue	$	5,852	$	4,778

Significant customers

The tables below present the significant customers on a percentage of total revenue basis for the three and nine months ended September 30, 2023 and 2022.

	Three months ended September 30,
	2023		2022
Customer A	13	%	15	%
Customer B	9	%	11	%
Customer C	—	%	10	%
Customer D	12	%	—	%
Customer E	12	%	—	%

	Nine Months Ended September 30,
	2023		2022
Customer A	2	%	13	%
Customer B	12	%	13	%
Customer C	12	%	—	%

Accounts receivable, contract assets and liabilities, and changes in deferred revenue

The following table provides information about account receivable, contract assets and liabilities as of September 30, 2023 and December 31, 2022 (in thousands):

	September 30,		December 31,
	2023		2022
Contract assets:
Trade accounts receivable, excluding unbilled receivables	$	395	$	757
Unbilled receivables1	368		58
Total contract assets	$	763	$	815
Contract liabilities:
Deferred revenue, current	$	2,177	$	1,781
Deferred revenue, noncurrent	92		9
Customer deposit2	45		45
Total contract liabilities	$	2,314	$	1,835

1 As of December 31, 2022, there was an immaterial amount of unbilled receivables classified as prepaid expenses and other current assets on the condensed consolidated balance sheets.

2Customer deposit is included in "Accrued expenses and other current liabilities" on the condensed consolidated balance sheets.

The allowance for doubtful accounts balance was nil as of September 30, 2023 and December 31, 2022, respectively.

Changes in deferred revenue from contracts with customers were as follows (in thousands):

	Nine months ended September 30, 2023
Balance at beginning of period	$	1,790
Deferral of revenue	4,353
Recognition of deferred revenue	(3,874)
Balance at end of period	$	2,269