Just hot stage a bunch of VMs and then there is no startup time. Every time someone finishes, just start another one and leave it running waiting for the next customer.
Starting the VM itself takes 20ms with Firecracker, the slowest part is starting the browser.
So there's no benefit on reusing the VM but not the browser. VM isolation is also important, customers can leave downloads and other files that should not be accessible for freshly created browsers on that same VM.
Oh my bad. You mean warm pools then. That works, yes, but you need to maintain that warm pool, which might not be ready if we receive a big burst of demand
Keeping the browser open and warm is also a problem, not all customers require the same features. The same engineering required to fix that (modifying values with Chromium open), also fixes the post-chromium snapshot
VM takes 20ms to start, browser around 300ms. Post-Chromium snapshot is at 50ms end-to-end, defeating the benefits of the warm pool you suggest, that will be our next step.
if people want custom features, then of course there is a cost to that. but if the majority of your customers are running on defaults, then there is a benefit. yes, it creates other issues, such as pool management, and if you do that wrong and you can't predict capacity well enough, then people get your "slow" path. but, overall, my experience is that the warm pools are extremely well regarded and not something that most people think of.
Following up like this--twice--is douchebaggy behavior. If someone misunderstands what you're saying, try elaborating or rephrasing instead. Help make the conversation more productive and less combative.