[kelseyfrog]

Category theory as it applies to programming is not dissimilar to learning design patterns. Some people go their whole careers never touching them and write perfectly fine programs. The same is true for category theory.

Those who learn either or both, have a larger set of mental abstractions that largely transcend any one programming language. They can say, this thing and that thing share a common salient property through a certain abstract pattern. There is a certain sense of mathematical beauty in recognizing common patterns and mechanisms. There is also the choice of subtly or drastically altering one's coding style. The same with each, a programmer can use just the right design pattern in just the right place and perhaps simplify or codify a section so that it's easier to understand the next time around (or decide not to!) or they can go completely wild and over-pattern their code. The same applies to category theory. One can recognize that some section is actually a closed reduction and accepts any semigroup and then decide to codify this into the program or not.

I tend to be a collector of ideas, so learning category theory and it's application in programming gives me all these little gems and ways to re-understabd code. Sometimes I use them and sometimes I don't, but my life is more joyful just knowing them regardless.