If you have layers that look like: view -> controller -> application services -> model/db, I focus most of my automated tests on everything at the application s

If you have layers that look like: view -> controller -> application services -> model/db, I focus most of my automated tests on everything at the application services. Critically, I don't mock our db, instead I focus on making setup and teardown fast. It seems to get me the most bang for my buck. Then I have a few end-to-end tests for more critical flows.