[ohyes]

Performance optimization is very simple. Make computer do less to get same or similar result. The most performant application does very little and still gets you the result you need.

To do this you must find ways to “cheat”. This can be of various forms. Better algorithms, better data structures, precomputation, caching. At some point you will exhaust low hanging fruit and need to dig into lower level aspects of the code or its compilation.

Anyway, best way to learn is to do it, go depth first and always check your work thoroughly. (It is easy to optimize yourself into a solution that is not working properly).