Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 123,903	$ 23,636
Short-term investments	69,443	82,453
Accounts receivable, net of allowances of $1,132 and $533 at December 31, 2021 and 2020, respectively	35,449	25,003
Inventory	21,958	36,329
Prepaid expenses and other current assets	5,049	3,943
Total current assets	255,802	171,364
Long-term investments	14,225
Property and equipment, net	27,500	16,531
Operating lease right-of-use assets	11,667	13,761
Other non-current assets	2,462	2,079
Goodwill	3,881	3,881
Total assets	315,537	207,616
Current liabilities:
Accounts payable	11,732	10,144
Accrued compensation and employee related benefits	6,365	5,529
Accrued and other current liabilities	2,481	1,468
Current portion of operating lease liabilities	4,143	3,641
Restructuring liabilities	591
Current portion of long-term debt	9,633
Current portion of deferred revenue	558	6,811
Total current liabilities	35,503	27,593
Long-term debt, net of current portion	278,661	54,556
Operating lease liabilities, net of current portion	11,934	15,266
Other long-term liabilities	279	805
Deferred revenue, net of current portion	236	277
Total liabilities	326,613	98,497
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock, $0.001 par value — 5,000 shares authorized, no shares issued and outstanding at December 31, 2021 and 2020
Common stock, $0.001 par value — 495,000 shares authorized, 24,737 and 23,350 shares issued and outstanding at December 31, 2021 and 2020, respectively	25	23
Additional paid-in capital	351,422	423,759
Accumulated other comprehensive (loss) income	(39)	3
Accumulated deficit	(362,484)	(314,666)
Total stockholders' equity	(11,076)	109,119
Total liabilities and stockholders' equity	$ 315,537	$ 207,616