[Answered ]-Django: per-customer customizations

You could utilize Django’s “site” framework for most of these.

Models can inherit from the original. They’re usually fetched in views, which you would adapt anyway.

You probably will want to re-architect your original app to facilitate extending it. This will pay off in other areas though so it’s probably worth the effort.

Look at some of the methods used to extend and customize contrib.admin. It’s a good example of an app that’s been designed with fairly good potential for extension and customization and it uses a variety of techniques.