Over a two-month period, contributed to biomejs/biome and goldbergyoni/vitest with a focus on reliability and compatibility. Addressed a bug in biomejs/biome by refining JSON import attribute detection, using JavaScript and Rust to trim whitespace and prevent false negatives, and updated tests to improve regression coverage. In goldbergyoni/vitest, enhanced the objectContaining utility to support symbol keys, aligning its behavior with Jest and improving cross-framework compatibility. This work involved core development and testing in TypeScript and JavaScript, emphasizing code analysis and robust test practices to ensure more accurate analytics and a smoother developer experience across both repositories.