[matchagaucho]

"Another issue is that my approach to software design has significantly changed. Where I would previously do a lot of inheritance and explicit design patterns, I’m far more motivated toward using composition, instead."

This, more than anything, has dramatically improved the quality of my designs... and made coding fun again.

Immutability and Lambda functions have also had a tremendous impact on my designs.

Is the term Object-Oriented-Programming relevant anymore?

[jameslk]

I don't see how preferring composition over inheritance makes OOP less relevant. In fact, GoF even suggests using composition over inheritance in OOP. Nor do I see how immutability and lambda functions are mutually exclusive to OOP either. You can have all of these things and still reap plenty of benefits from OOP. The benefits of OO polymorphism and several decades worth of architectural design patterns are not irrelevant just because functional programming concepts exist. Both should be used advantageously and when appropriate.

[matchagaucho]

It's possible to do Functional Programming with an OO language these days using anonymous methods/Lambdas.

The GoF patterns either need updating or perhaps we're on the verge of calling this hybrid environment something completely different (?)