Worked on backend stability and dependency management across the langchain-ai/langsmith-sdk and modelscope/data-juicer repositories, focusing on Python package management and unit testing. Addressed a bug in langsmith-sdk by implementing robust urllib3 version parsing using packaging.version.parse, ensuring compatibility with PEP 440 local-version identifiers and preventing runtime errors during Client construction. Added regression tests to validate these changes across multiple version formats. In modelscope/data-juicer, replaced the bs4 stub with beautifulsoup4 to streamline dependency resolution and improve import reliability. These updates reduced runtime errors, improved deployment reliability, and simplified downstream maintenance, as confirmed by comprehensive regression test coverage.