Contributed to the awslabs/llrt repository by enhancing request handling robustness and extending buffer utilities to improve reliability for downstream systems. Developed and integrated static methods Buffer.isBuffer and Buffer.isEncoding using TypeScript and Node.js Buffer API, enabling more reliable buffer validation and encoding checks. Addressed a cast error in request options by implementing safe handling for undefined or null values, ensuring correct request object creation and reducing runtime errors. Expanded unit test coverage to verify new behaviors and prevent regressions, demonstrating a focus on maintainability. Applied skills in error handling, Rust, and test-driven development to strengthen core system reliability.