Why your architecture is functional and how to deal with it

If your project isn't some ancient legacy, most likely it's based on some cutting-edge architectural concept: CQRS, for example, or DDD, or maybe Actor Model. It doesn't matter which one, because all of them are connected to functional programming, one way or another. And even if you wear an "OOP only and forever" T-shirt, odds are you still write functional code every day.

How this came to be, how it's usually manifested, how you're supposed to deal with it and how understanding of functional architecture fundamentals can help you make your code better? That's what we're going to discuss.