Comment by jasonjmcghee

Recompile and hot reload, maybe. 2 seconds if you're very lucky. Many setups are much slower. I've seen some really cool projects over the last few years- things like tcc + hot reload that have really good turn around time.

But "live" is a whole different thing. And most languages aren't built with the expectation that you'll be patching it while it's running - at least as standard operating procedure and without nuking state.

And that's a key part.

I think you should be able to build an app and develop a game without ever having to restart them.

And that would come with new challenges and the need for new tooling / constructs. E.g. When you change a type / structure, and there's existing state, what happens? (migration, deletion etc)