[lupire]

If you are rigorous as to make classes final, you should also be rigorous to never provide a non-interface as an Application Programming Interface.

Google uses mocks and fakes implementations of interfaces, and provides dependency injection frameworks for managing these (Guice and Dagger).

[stickfigure]

I once worked with a guy who obsessively made interfaces for every java class. Even domain objects. He was extremely proud of this.

It was garbage.

[redditor98654]

Was this in Amazon? If so, it might have been me. Sorry about that. I have learnt my lesson now.

I don’t recall doing it for domain objects though.