[Django]-Large(ish) django application architecture

For testing, you should mock your dependencies. The logging and mailing component, for example, should be mocked during unit testing of the views. I would usually use python-mock, this allows your views to be tested independently of the logging and mailing component, and vice versa. Just assert that your views are calling the right service calls and mock the return value/side effect of the service call.

You should also avoid touching the database when doing tests. Instead try to use as much in memory objects as possible, instead of Application.objects.create(), defer the save() to the caller, so that you can test the services without having to actually have the Application in the database. Alternatively, patch out the save() method, so it won’t actually save, but that’s much more tedious.

First, try to brake down your big task into smaller classes. Connect them with usual method calls or Django signals.

If you feel that the sub-tasks are independent enough, you can implement them as several Django applications in the same project. See the Django tutorial, which describes relation between applications and projects.