> The reasoning would always be "this can change!" As I understood Uncle Bob's argument for using interfaces though, the main benefit is not supporting alterna

> The reasoning would always be "this can change!" As I understood Uncle Bob's argument for using interfaces though, the main benefit is not supporting alternative implementations, but rather aiding in the enforcement of the Dependency Rule[1] and of the Single Responsibility Principle[2]. Interfaces make the relation between components explicit in two ways: - they make it clear what depends on what - they make it clear what are the responsibilities of the components on either side of the interface So aside from the fact that it might make it easier in the future to swap implementations, it first makes it easier when writing the code to decide how to organize its components (i.e. laying out its architecture). Of course I agree with you that interfaces can definitely be abused, and can make code more indirect and difficult to read. I just wanted to point out what I think is Uncle Bob's point. :) [1] https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html#the-dependency-rule https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-a... [2] https://en.wikipedia.org/wiki/Single_responsibility_principle https://en.wikipedia.org/wiki/Single_responsibility_principl...