albertzeyer's example with Notch explains the issue pretty well: When working on a video game, restarting the game every time you are tweaking the behaviour of

albertzeyer's example with Notch explains the issue pretty well: When working on a video game, restarting the game every time you are tweaking the behaviour of an entity takes a lot of time. Hot code reloading while keeping the state of the game makes development much easier. On the other hand, when the entire state is stored outside of the Python app (eg: a web app using a database), restarting the entire process and reloading the page is fast enough and more reliable.