[fhuici]

[Disclaimer: I'm with KraftCloud] For what it's worth, Firecracker/the VMM is only one part of the boot process. Among others, there's also the controller and the VM/OS itself that typically slow things down. In other words, it's not enough to just switch in Firecracker and expect cold starts to immediately drop to sub-second levels.

On kraft.cloud we've fundamentally redesigned the cloud stack to be able to cold start containers/VMs in milliseconds (eg, about 20 millis for nginx, about 50 millis for a basic Node app), and also scale them to zero and autoscale them in milliseconds. If interested there's more info about the tech in our blog posts https://unikraft.io/blog/ .