Should I worry about the speed of the program with interfaces?

Question

Java

I am writing a client-server in kotlin-java and I like to do everything through interfaces, implementing something specific only in the final places, but I think there is some limit to these levels of abstraction? On the pluses, we were taught that this has a bad effect on performance, and I'm afraid that then everything will have to be rewritten into a mess from classes ...

Answer 1

This does not affect performance in any way, but with abstractions you can really go too far, there is even a term for this - overengineering