Programming languages that I use or know a thing or two about:

• Crystal
• Go
• Ruby
• Rust
• Zig

Design:

• Programming language design
• Writing cross-language implementation is difficult
• Programming languages resources

Implementation:

• Choices for lexing and parsing in Ruby
• Books I like
  • Crafting Interpreters (Robert Nystrom)
  • Language Implementation Patterns (Terence Parr)