Stock-based compensation (Tables)

12 Months Ended

Sep. 28, 2019

Share-based Payment Arrangement [Abstract]

Schedule of stock option activity

The summary of the Company’s stock option activity is as follows:

	Number of Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value
					(in years)	(in thousands)
Outstanding at September 29, 2018	48,504,182		$	10.33	6.6	$	276,959
Granted	1,714,328		13.34
Exercised	(7,925,897	)	3.98
Forfeited	(5,137,045	)	13.48
Outstanding at September 28, 2019	37,155,568		$	11.39	6.3	$	94,288
At September 28, 2019
Options exercisable	26,436,074		$	10.23	5.5	$	92,281
Options vested and expected to vest	35,606,324		$	11.25	6.2	$	93,836

Schedule of fair value of options

The fair value of options at the date of grant was estimated with the following weighted-average assumptions:

	2019		2018		2017
Expected term (years)	6.51		6.25		6.25
Risk-free interest rate	2.67	%	2.73	%	1.95	%
Expected volatility	30.7	%	30.2	%	32.4	%
Expected dividend yield	—	%	—	%	—	%

Schedule of restricted stock unit activity

The summary of the Company’s unvested RSU activity is as follows:

	Number of Units		Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value
					(in thousands)
Outstanding at September 29, 2018	—		$	—	$	—
Granted	7,915,980
Exercised	(829,270	)
Forfeited	(369,924	)
Expired	—
Outstanding at September 28, 2019	6,716,786		$	11.4	$	90,744
At September 28, 2019
Units expected to vest	5,207,691		$	11.4	$	70,356

Schedule of stock-based compensation expense

Total stock-based compensation expense by function category was as follows:

	2019		2018		2017
(In thousands)
Cost of revenue	$	985	$	198	$	240
Research and development	17,643		13,960		13,605
Sales and marketing	12,965		15,885		15,086
General and administrative	14,982		8,602		7,619
Total stock-based compensation expense	$	46,575	$	38,645	$	36,550