Hello again! Cold starts depend a lot on what people actually deploy. They're really fast for an optimized Go binary, really slow for most Node apps. We were p

Hello again! Cold starts depend a lot on what people actually deploy. They're really fast for an optimized Go binary, really slow for most Node apps. We were playing with Deno + OSv just today and got an app to boot and accept an HTTP request in about 20ms. That assumes you have the root fs all built and ready to go, though, pulling down images and prepping everything is a bit of a bottleneck for that. We looked at gvisor pretty hard but preferred more traditional virtualization. We didn't look much at other virtualization options, Firecracker was really good from day one. The docs were pretty good. We ended up having to build a bunch, though, probably just because of the nature of our product. We built a custom init (in Rust), a Docker image to root fs builder, and a nomad task driver (both in Go). The init includes and rpc mechanism so we can communicate with the VM. Firecracker was pretty easy, building the scaffolding to use it was a little harder, but the vast majority of our time is spent on the dev UX and proxy/routing layer.