How to make Ruby faster for command line scripts
time ruby --disable-gems your-script.rb
This has significant speedup on my machine, of course if you need some gems then you shouldn't do this.
Consider also: – crystal (compiled ruby-like, but not Ruby per se) – mruby (lightweight Ruby)
I haven't managed to get mruby to do what I want with a YAML gem, but that's OK since all this is just premature optimization instead of writing the software I need to write.