Balance Sheet Components - Summary of changes in allowance for doubtful accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 03, 2020	Sep. 28, 2019	Sep. 29, 2018
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 1,255	$ 872	$ 804
Increases	1,127	1,034	635
Write-offs	(1,075)	(651)	(567)
Ending balance	$ 1,307	$ 1,255	$ 872