If agents are good at RoR, it's ironic because they're bad at Ruby. They aren't good at holding a model of the 20 different things various code you've loaded has monkey patched, no longer respecting their original contracts.
This is coming from someone working 13 years as Ruby dev. I love the language, but I want to be honest that I didn’t had experience with other languages before and seeing statically typed languages (Java, TypeScript), Elixir opened my mind to the amount of cargo cult inside Ruby community stemming mostly from people limited to knowing only 1 language.