Stock-based compensation (Tables)

6 Months Ended

Mar. 28, 2020

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, 2019	37,155,568		$	11.39	6.3	$	94,288
Granted	—
Exercised	(2,186,674	)
Forfeited	(892,262	)
Outstanding at March 28, 2020	34,076,632		$	11.67	5.9	$	34,439
At March 28, 2020
Options exercisable	26,650,301		$	10.94	5.4	$	34,439
Options vested and expected to vest	33,117,267		$	11.59	5.9	$	34,439

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)
Unvested at September 29, 2019	6,716,786		$	11.40	$	90,744
Granted	1,572,617
Vested	(923,636	)
Forfeited	(382,429	)
Unvested at March 28, 2020	6,983,338		$	11.99	$	60,196
At March 28, 2020
Units expected to vest	5,648,433		$	12.00	$	48,689

Schedule of stock-based compensation expense

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

	Three Months Ended				Six Months Ended
	March 28, 2020		March 30, 2019		March 28, 2020		March 30, 2019
(In thousands)
Cost of revenue	$	278	$	218	$	561	$	403
Research and development	5,427		4,284		10,543		7,888
Sales and marketing	3,407		3,128		6,948		5,809
General and administrative	4,282		3,456		8,546		6,018
Total stock-based compensation expense	$	13,394	$	11,086	$	26,598	$	20,118