[magicalhippo]

You don't have to use OO though. We're using an OO-oriented language at work, but I do a lot of de-duplication of code by extracting common functions.

If needed I can delegate the specialization to an interface or in a function reference parameter (so anonymous functions can be passed) rather than in a subclass.

When implementing the interfaces I might use subclasses though, if I have some very similar variants.