As a Java engineer in the web development industry for several years now, having heard multiple times that X is good because of SOLID principles or Y is bad because it breaks SOLID principles, and having to memorize the “good” ways to do everything before an interview etc, I find it harder and harder to do when I really start to dive into the real reason I’m doing something in a particular way.
One example is creating an interface for every goddamn class I make because of “loose coupling” when in reality none of these classes are ever going to have an alternative implementation.
Also the more I get into languages like Rust, the more these doubts are increasing and leading me to believe that most of it is just dogma that has gone far beyond its initial motivations and goals and is now just a mindless OOP circlejerk.
There are definitely occasions when these principles do make sense, especially in an OOP environment, and they can also make some design patterns really satisfying and easy.
What are your opinions on this?
If you are creating interfaces for classes that will not have second implementation, that sounds suspicious, what kind of classes are you abstracting? Are those classes representing data? I think I would be against creating interfaces for data classes, I would use records and interfaces only in rare circumstances. Are you complaining about abstracting classes with logic, as in services/controllers? Are you creating tests for those? Are you mocking external dependencies for your tests? Because mocks could also be considered different implementations for your abstractions. Some projects I saw definitely had taken SOLID principles and made them SOLID laws… Sometimes it’s an overzealous architect, sometimes it’s a long-lasting project with no original devs left… The fact that you are thinking about it already puts you in front of many others…
SOLID principles are principles for Object Oriented programming so as others pointed out, more functional programming might give you a way out.