Worked on targeted reliability improvements across the puppeteer/puppeteer and langgenius/dify repositories, focusing on robust error handling and configuration validation. Addressed a configuration issue in puppeteer/puppeteer by implementing logic to reject unsupported blocklist and allowlist parameters for WebDriver BiDi connections, ensuring protocol-specific restrictions are enforced and validated through expanded unit tests. In langgenius/dify, enhanced the document creation API by raising a clear ValueError when the required indexing_technique parameter is missing, improving developer feedback and reducing debugging time. Utilized Python, TypeScript, and Node, applying full stack development and testing skills to deliver maintainable, well-tested solutions that improve developer experience.