If you enjoyed the state machine + parsing part and also I recommend the older "Lexical Scanning in Go" talk that Rob Pike gave: https://www.youtube.com/watch?v=HxaD_trXwRE

It's in Go, but you can apply most of it easily in other languages.

I'm so happy that modern languages like Rust, Zig, and Go support unicode/runes/graphemes natively. So many problem just disappear compared to Java, .net, C++, or scripting languages.