> Heroku is a great example of immutable servers in action: every change to your application requires a ‘git push’ to overwrite the existing version. Um, not i

> Heroku is a great example of immutable servers in action: every change to your application requires a ‘git push’ to overwrite the existing version. Um, not it's not. Heroku's buildpacks code caches a hell of a lot of stuff on each execution agent. Still more code has to recognise and try to repair various broken states. It's mutability, through and through.