Tadeo enhanced macro system capabilities in the rust-lang/rust and rust-lang/rust-analyzer repositories by introducing lifetime repeats support, enabling more expressive macro patterns and improving parsing logic. Through careful code refactoring and metaprogramming in Rust, Tadeo updated macro expansion to handle lifetime separators and improved the pretty-printing logic using is_any_identifier, which increased the accuracy of identifier handling and test output formatting. By addressing formatting inconsistencies in macro expansion tests, Tadeo improved test reliability and developer experience. The work demonstrated a strong grasp of Rust compiler internals, macro development, and testing, delivering robust, maintainable improvements within a short timeframe.