At a previous job I wrote a docker build for patching individual Java class files on top of a monolithic docker image. This was not runtime patching, but allowed a single layer that was only a few kilobytes to be deployed quickly in emergency situations.
Interestingly, it had similar constraints and checked them at build time: it could not be a public ABI change and only one patch at a time.
The world could use more hot patching. Now that AI upends computer security, getting software patched in a timely fashion is more important than ever, and having to reboot/restart the process or computer to get those updates is more of a problem than it was before.
I don't understand the joke. My background is worked at Ksplice a long time ago, patching the Linux kernel for security fixes without having to reboot.
Interestingly, it had similar constraints and checked them at build time: it could not be a public ABI change and only one patch at a time.