In recent years, Ruby's type ecosystem has been growing steadily. More and more production applications are benefiting from type checking. However, as AI-generated Ruby code continues to improve in quality, I find myself questioning more often: do we really need types?

In this session, I'll share my realization that most of the benefits of typing really boil down to preventing NoMethodError. Based on this, I'll introduce Method-Ray, a gem I'm developing that provides this benefit without requiring any type annotations. I will cover its usage, development background, current architecture (implemented in Rust), and how it differs from existing type checkers.