I agree that 100% functional is not necessarily the way to go. That said, I am a big fan of F#'s "functional first" ethos, which drives you toward that sweet sp

I agree that 100% functional is not necessarily the way to go. That said, I am a big fan of F#'s "functional first" ethos, which drives you toward that sweet spot of a functional core inside of an imperative shell. With C#, when I'm trying to use functional design, I often feel like I'm swimming against the current. The language has functional features, and it will certainly let you use them, but, LINQ aside, the path of least resistance is mostly imperative and object-oriented. In F#, it's the other way around. It has a full suite of object-oriented features - still, after all these years, quite a bit more complete than C#'s suite of functional features - but the path of least resistance is mostly functional. I don't want to say that's a universal best way to have things. But it suits my taste, because it makes the easiest way to do things correspond very closely with the way I like to see things done: distinct and well-distinguished layers of functional and object-oriented code, sorted according to where each is of the most utility. C#, by contrast, tends to guide you toward a foamy lather of functional and object-oriented code with no identifiable organizing principle.