Would learning category theory be useful in my programming career?

Short answer: no.

Even the heavy 'category theory' stuff that some Haskellers are fond of is only loosely related to results of any depth in category theory. To really get anything out of category theory, you need to already have quite a broad and deep mathematical knowledge base.

Deepening your knowledge of linear algebra or general computer science concepts would almost certainly be more valuable.

That said, if category theory interests you, why not? I'm just talking about practical value here.

I suppose you learned about category theory through Haskell? I did, and I was wondering the same question as you. After doing some investigation and looking what others say, it turned out that "real" category theory is only loosely related to Haskell, and isn't necessary to understand it to work in Haskell. I then didn't go deeper down that rabbit hole :D.

But, from my experience, already learning Haskell would improve ones programming skills, especially if you haven't been exposed to the functional programming before. It is really a mind-changer and equips you with new perspectives which you can use in other programming languages as well.

So I would definitely recommend investigating Haskell, and maybe after some time you can then also go into the actual Category Theory and see how it connects to your Haskell knowledge.

Short answer: No, absolutely not. Your time and efforts would be much better spent learning more about any else on a standard CS curriculum

See Please Don't Learn Category Theory (2013): https://news.ycombinator.com/item?id=7066314