During June 2025, this developer contributed to the sorbet/sorbet repository by implementing a dedicated IO::TimeoutError type definition in Ruby. The new class, inheriting from IOError, was designed to represent IO timeouts raised by IO#timeout=, providing clearer error semantics and enabling more robust type checking. By introducing this type definition, the developer improved the diagnosability and classification of IO-related errors, laying the foundation for safer handling and retry patterns in downstream code. Their work focused on enhancing type safety and error clarity within Ruby, leveraging skills in type definitions to address a nuanced aspect of IO error management.