Income Taxes - (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

Loss before provision for income taxes consisted of the following:

	Year Ended December 31,
	2019			2018			2017
	(in thousands)
Domestic	$	(56,675	)	$	(33,422	)	$	(16,939	)
Foreign	36			68			20
Total	$	(56,639	)	$	(33,354	)	$	(16,919	)

Our provision for (benefit from) income taxes consisted of the following:

	Year Ended December 31,
	2019			2018		2017
	(in thousands)
Current:
U.S. Federal	$	—		$	—	$	—
State	20			7		2
Foreign	7			21		6
Total current	$	27		$	28	$	8
Deferred:
U.S. Federal	$	(1,064	)	$	—	$	(61	)
State	(332		)	—		(8		)
Foreign	—			—		—
Total deferred	$	(1,396	)	$	—	$	(69	)
Total provision for (benefit from) income taxes	$	(1,369	)	$	28	$	(61	)

Schedule of Effective Income Tax Rate Reconciliation

The reconciliation of federal statutory income tax rate to our effective income tax rates is as follows:

	Year Ended December 31,
	2019		2018		2017
Expected income tax benefit at the federal statutory rate	21.00	%	21.00	%	34.00	%
State taxes, net of federal benefit	(0.06	)	(0.01	)	0.04
Foreign losses taxed at different rates	(0.01	)	(0.11	)	—
Research and development credit, net	4.39		2.79		3.56
Tax Cuts and Jobs Act revaluation	—		—		(57.00	)
Non-deductible items	(0.97	)	(0.53	)	(1.15	)
Stock-based compensation	12.00		2.59		1.90
Other	0.03		0.76		(0.85	)
Release of valuation allowance due to acquisition	2.47		—		—
Change in valuation allowance	(36.43	)	(26.57	)	19.86
Total	2.42	%	(0.08	)%	0.36	%

Schedule of Deferred Tax Assets and Liabilities

Significant components of our deferred tax assets are summarized as follows:

	Year Ended December 31,
	2019			2018			2017
	(in thousands)
Deferred tax assets:
Federal and state net operating loss carryforwards	$	45,193		$	31,508		$	15,307
Research and development tax credits	7,771			3,794			2,127
Stock-based compensation	8,434			2,055			585
Accruals and reserves	1,270			1,009			405
Deferred revenue	4,127			2,487			1,286
Other	573			230			71
Gross deferred tax assets	67,368			41,083			19,781
Valuation allowance	(59,267		)	(38,310		)	(19,302		)
Net deferred tax assets	$	8,101		$	2,773		$	479
Deferred tax liabilities:
Property and equipment	(2,450		)	(1,313		)	(436		)
Acquired intangible assets	(4,119		)	(1,460		)	(43		)
Prepaid insurance and deferred commissions	(1,532		)	—			—
Net deferred tax liabilities	$	(8,101	)	$	(2,773	)	$	(479	)
Net deferred tax assets	$	—		$	—		$	—

Summary of Operating Loss Carryforwards

As of December 31, 2019, 2018 and 2017, we had net operating loss carryforwards and tax credit carryforwards as follows:

	Year Ended December 31,
	2019		2018		2017
	(in thousands)
Net operating losses, federal	$	189,284	$	122,824	$	66,906
Net operating losses, California	9,512		6,251		3,144
Net operating losses, other states	80,808		57,494		11,396
Tax credits, federal	6,630		3,312		2,070
Tax credits, state	4,258		2,273		1,292
Total	$	290,492	$	192,154	$	84,808

Summary of Income Tax Contingencies

A reconciliation of the beginning and ending balances of the unrecognized tax benefits during the years ended December 31, 2019, 2018 and 2017 is presented below:

	Year Ended December 31,
	2019		2018		2017
	(in thousands)
Unrecognized benefit—beginning of year	$	1,791	$	1,235	$	—
Gross increases—current year tax positions	1,326		556		337
Gross increases—prior year tax positions	—		—		898
Decreases—prior year tax positions	—		—		—
Unrecognized benefit—end of year	$	3,117	$	1,791	$	1,235