v3.10.0.1
Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Cash flows from operating activities:      
Net loss $ (8,857) $ (63,509) $ (42,758)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:      
Depreciation and amortization 8,389 5,336 5,302
Stock-based compensation expense 37,674 10,953 8,206
Provision for doubtful accounts 876 104 336
Change in fair value of preferred stock warrant liability   40,333 (888)
Noncash interest expense 342 784 115
Loss from exit of facilities 1,120 525 3,804
Loss on disposals of property and equipment 8 54 29
Loss from extinguishment of debt   2,338  
Write-off of deferred initial public offering costs     594
Impairment of long-lived assets 352   320
Amortization of premiums on short-term investments (357)    
Changes in operating assets and liabilities:      
Accounts receivable (50,673) (41,184) (26,354)
Inventories (2,953) 10,828 (13,256)
Prepaid expenses and other current assets (306) (6,514) (544)
Deferred cost of revenue 2,261 (1,959) (2,885)
Other noncurrent assets (732) (2,794) 448
Accounts payable (98) 24,315 (2,808)
Accrued liabilities 17,914 24,127 17,796
Other long-term liabilities (1,101) 3,579 294
Deferred revenue 10,063 29,976 19,786
Net cash provided by (used in) operating activities 13,922 37,292 (32,463)
Cash flows from investing activities:      
Purchase of property and equipment (18,327) (9,229) (8,596)
Purchase of business, net of cash acquired   (2,959)  
Purchases of short-term investments (53,806)    
Sales/maturities of short-term investments 12,000    
Change in deposits   (80) 29
Net cash used in investing activities (60,133) (12,268) (8,567)
Cash flows from financing activities:      
Payments of costs related to initial public offering     (594)
Proceeds from borrowings, net   24,691 15,000
Repayments of borrowings   (40,446) (15,000)
Holdback payment for a prior business acquisition (500)    
Proceeds from equity issued under incentive plans, net of repurchases 25,025 1,773 438
Proceeds from issuance of common stock pursuant to an initial public offering, net of issuance costs of $3.1 million   131,646  
Net cash provided by financing activities 24,525 117,664 (156)
Net (Decrease) Increase in Cash (21,686) 142,688 (41,186)
Cash and cash equivalents—Beginning of period 177,250 34,562 75,748
Cash and cash equivalents—End of period 155,564 177,250 34,562
Supplemental disclosures of cash flow information:      
Cash paid for interest 493 1,149 236
Cash paid for income taxes 564 222 121
Supplemental disclosures of noncash investing and financing activities:      
Unpaid portion of property and equipment purchases $ 1,617 1,250 $ 306
Fair value of preferred stock warrants reclassified to additional paid in capital   52,355  
Issuance of convertible preferred stock warrants in connection with debt   $ 2,032