Ryou developed a targeted lint rule refinement for the biomejs/biome repository, focusing on improving the noUnusedVariables rule in TypeScript ambient contexts. By updating the rule to ignore type parameters declared within ambient module blocks, Ryou addressed a source of false positives that previously disrupted developer workflows and CI stability. The solution was implemented using Rust and TypeScript, with comprehensive test coverage added to ensure reliability and prevent regressions. This work reduced unnecessary lint warnings, enhancing the overall developer experience. The depth of the contribution lay in its precise scope and the careful attention to both correctness and maintainability within the codebase.