“The bug bounty reward gets divided between files, eg if a fix to a $1000 bug changed 5 files, each file gets $200”
Map Chrome bug bounty payouts onto the files the fixes touched and the total comes to $9,873,277 through early November 2023. UI code alone accounts for $1,150,481. Google pays outsiders to find what its own engineers keep shipping. Ten million dollars is cheap next to one exploited zero-day in three billion browsers.