CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Cash flows from operating activities
Net loss	$ (37,607)	$ (46,156)	$ (27,300)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,575	2,758	1,377
Amortization of deferred commissions	4,004	2,834	1,384
Stock-based compensation	9,452	10,568	1,807
Change in fair value of preferred stock warrant liability	627	190	50
Other non-cash items	355
Changes in operating assets and liabilities net of effects from acquisitions:
Accounts receivable	(20,041)	(8,314)	(8,659)
Prepaid expenses and other current assets	(4,600)	(1,289)	(807)
Other assets	(1,136)	(2,006)	(591)
Deferred commissions	(4,468)	(5,384)	(3,161)
Accounts payable	224	(121)	368
Accrued expenses and other liabilities	1,772	696	7,277
Deferred revenue	25,888	24,155	16,326
Net cash used in operating activities	(20,955)	(22,069)	(11,929)
Cash flows from investing activities
Purchase of property and equipment	(4,491)	(3,868)	(2,370)
Acquisitions, net of cash acquired	(6,750)	(1,426)
Net cash used in investing activities	(11,241)	(5,294)	(2,370)
Cash flows from financing activities
Proceeds from issuance of common stock, net of underwriting discounts, commissions and offering costs	137,216	(64)
Proceeds from the exercise of common stock options	4,252	1,570	466
Excess tax benefit from stock-based compensation	51
Proceeds from issuance of convertible preferred stock, net of issuance costs		75,731	39,972
Proceeds from the exercise of preferred stock warrants	50	500
Net cash provided by financing activities	141,569	77,737	40,438
Net increase in cash and cash equivalents	109,373	50,374	26,139
Cash and cash equivalents at beginning of period	92,348	41,974	15,835
Cash and cash equivalents at end of period	201,721	92,348	41,974
Supplemental disclosure of cash flow data
Cash paid for income taxes	390	17	8
Supplemental disclosure of non-cash investing and financing activities
Issuance of common stock in connection with acquisitions	2,357	1,269
Vesting of early exercised stock options	606	142	86
Property and equipment included in accounts payable and accrued expenses and other current liabilities	84	184	$ 43
Conversion of convertible preferred stock to common stock	$ 164,950
Offering costs included in accounts payable and accrued expenses and other current liabilities		$ 1,254