This question is related but doesn't directly answer my question.
I can imagine that understanding category theory helps someone who is designing a programming language, apparently in particular functional programming languages.
But what I find hard to understand is, how would a software engineer benefit from a knowledge of category theory, who has no interest in designing a new language, but just wants to solve practical problems.
Could you explain any benefit it has? Let's assume the software engineer who writes in functional programming languages. How would he/she benefit from a knowledge of category theory?
I would like to get a more illustrative answer than merely "it helps you to understand functional programming better", because I've heard multiple lectures on category theory make a claim like that, but it has not become clear to me how, practically, it actually helps you.