Revenue (Tables)

6 Months Ended

Jun. 30, 2022

Revenue

Schedule of revenue by discipline

	Three months ended				Six months ended
	June 30,				June 30,
	2022		2021		2022		2021
	(in thousands)
Systems	$	165,350	$	100,138	$	317,152	$	181,129
Aftermarket		55,827		47,136		107,620		98,921
Total Revenue	$	221,177	$	147,274	$	424,772	$	280,050

Schedule of revenue by geographic markets

	Three months ended				Six months ended
	June 30,				June 30,
	2022		2021		2022		2021
	(in thousands)
North America	$	34,683	$	10,204	$	59,596	$	19,712
Asia Pacific		168,705		116,642		317,945		220,033
Europe		17,789		20,428		47,231		40,305
Total Revenue	$	221,177	$	147,274	$	424,772	$	280,050

Schedule of Contract liabilities

	June 30,		December 31,
	2022		2021
	(in thousands)
Contract liabilities	$	71,549	$	68,436

Contract liabilities are reflected as deferred revenue on the consolidated balance sheet and relate to payments invoiced or received in advance of completion of performance obligations under a contract. Contract liabilities are recognized as revenue upon the fulfillment of performance obligations.

	Three months ended				Six months ended
	June 30,				June 30,
	2022		2021		2022		2021
	(in thousands)
Balance, beginning of the period	$	74,840	$	22,142	$	68,436	$	23,058
Deferral of revenue		28,703		21,893		46,697		30,117
Recognition of deferred revenue		(31,994)		(8,517)		(43,584)		(17,657)
Balance, end of the period	$	71,549	$	35,518	$	71,549	$	35,518