I second this recommendation! I agree with the sentiment expressed by some in these comments that intermediate category theory probably isn’t going to help you too much as a programmer. However the introduction to Category Theory in “Conceptual Mathematics” caused me to understand sum types, product types, algebraic data types, finite state automata, logic, and functions as objects in a new way. Additionally “Conceptual Mathematics” isn’t arcane or inaccessible they mention in the introduction (or maybe it was a review of the book) that a motivated high school student could use the book for self study.