Balance Sheet Components

Inventory

Inventory consists of the following (in thousands):



	As of January 31, 2019		As of April 30, 2019
Raw materials	$	3,349	$	8,490
Finished goods	41,338		37,446
Inventory	$	44,687	$	45,936

Property and Equipment, Net

Property and equipment, net consists of the following (in thousands):



	As of January 31, 2019			As of April 30, 2019
Test equipment	$	170,930		$	180,148
Computer equipment and software	117,330			128,610
Furniture and fixtures	6,980			7,678
Leasehold improvements	34,286			36,002
Total property and equipment	329,526			352,438
Less: accumulated depreciation and amortization	(204,173		)	(223,253		)
Property and equipment, net	$	125,353		$	129,185

Depreciation and amortization expense was $16.0 million and $19.8 million for the three months ended April 30, 2018 and 2019.

Intangible Assets, Net

Intangible assets, net consist of the following (in thousands):



	As of January 31, 2019							As of April 30, 2019
	Gross Carrying Value		Accumulated Amortization			Net Carrying Amount		Gross Carrying Value		Accumulated Amortization			Net Carrying Amount
Technology patents	$	10,125	$	(6,572	)	$	3,553	$	10,125	$	(6,948	)	$	3,177
Developed technology	17,700		(1,135		)	16,565		56,100		(2,057		)	54,043
Intangible assets, net	$	27,825	$	(7,707	)	$	20,118	$	66,225	$	(9,005	)	$	57,220

Intangible assets amortization expense was $0.4 million and $1.3 million for the three months ended April 30, 2018 and 2019. As of April 30, 2019, the weighted-average remaining amortization period was 2.1 years for technology patents and 6.8 years for developed technology. Amortization of the technology patents is included in general and administrative expenses due to their defensive nature and amortization of developed technology is included in cost of product revenue in the condensed consolidated statements of operations.

As of April 30, 2019, future expected amortization expense for intangible assets is as follows (in thousands):



Fiscal Years Ending January 31,	Estimated Future Amortization Expense
Remainder of 2020	$	7,138
2021	9,518
2022	8,560
2023	8,014
2024	8,014
Thereafter	15,976
Total	$	57,220

Goodwill

The change in the carrying amount of goodwill is as follows (in thousands):



	Amount
Balance as of January 31, 2019	$	10,997
Goodwill acquired	25,410
Balance as of April 30, 2019	$	36,407

Accrued Expenses and Other Liabilities

Accrued expenses and other liabilities consist of the following (in thousands):



	As of January 31, 2019		As of April 30, 2019
Taxes payable	$	7,146	$	7,550
Accrued marketing	6,173		7,560
Accrued travel and entertainment expenses	3,570		4,227
Acquisition consideration held back	3,725		3,725
Other accrued liabilities	19,246		24,330
Total accrued expenses and other liabilities	$	39,860	$	47,392