Worked on enhancing error handling and dependency management in Rust-based libraries over a two-month period. In the luanfujun/uv repository, developed a public-facing ErrorTree API, exposing internal error structures to external users and enabling more effective conflict analysis without breaking backward compatibility. Focused on library development and robust error handling to support advanced diagnostics and tooling. In the conda/rattler project, upgraded core dependencies Resolvo and Petgraph, updating Cargo.toml and Cargo.lock to ensure stable downstream integrations. Refactored code to accommodate new APIs, emphasizing reproducible builds and future-proofing the codebase through careful dependency management and targeted Rust refactoring.