During February 2026, Daichi Kudo focused on enhancing the reliability of file handling in the rails/rails repository by addressing a specific issue within ActiveStorage. He implemented a targeted fix in Ruby on Rails to handle cases where the content_type attribute of ActiveStorage::Blob could be nil, which previously led to runtime errors during blob type checks. By updating backend logic and introducing regression tests, Daichi ensured that blob-type checking methods now return false when content_type is absent, thereby improving robustness in production environments. His work demonstrated careful attention to backend development and thorough testing practices using Ruby and Rails.