Python startup time: milliseconds matter
Should be able to hot boot the VM with the right tooling. You can reuse HPC "checkpoint" code from supercomputing environments as a generic hammer for Python/Ruby/JVM. Some Russians figured out how to do it in userspace without a kernel mod: <a href="https://criu.org/Main_Page" rel="nofollow">https://criu.org/Main_Page</a>