[agentultra]

I echo others: follow your nose. Build things. Find an open source project that interests you, pick a low hanging bug, fix it. Do it again. Work on harder issues. Try implementing a requested feature.

Start a greenfield project. Something that isn’t huge in scope. A basic text editor, a mini redis clone, an asteroids game. Try something harder for your next project.

Theory-wise I think type theory is a good start. Along with with Software Abstractions; a great book on the design of software systems using formal methods. And a book or two on data structures and algorithms. Discrete maths essentially and combinatorics. That will get you far.