Everyone's favourite subset of functional features is different, of course. I am still early in my career. I'm still discovering stuff for first time. I've als

Everyone's favourite subset of functional features is different, of course. I am still early in my career. I'm still discovering stuff for first time. I've also found that I am much more likely to use streams, lambdas, Optional and predicates in code compared to my more experienced colleagues. My functions tend to be pure more often, code has more interfaces than inheritance and generally more unit testable. One of the surprising moments was learning Elixir and realising I'm already doing the pipe thing in Java with Optional.map(). Java will never shed its OO skin but it is starting to grow FP muscles in the right places.