Worked on the infiniflow/ragflow repository to enhance the stability and reliability of the Docling parsing workflow. Addressed a critical bug by updating the Python type hint for the DoclingParser._transfer_to_sections method, ensuring compatibility with 3-item tuples and preventing runtime crashes during document chunking and section transfer. This backend development effort involved careful Python typing refinements and targeted refactoring to align the codebase with actual data structures, reducing downstream failures. Collaborated with other contributors to deliver the fix, focusing on maintainability and cross-team communication. The work demonstrated attention to detail in backend Python development and robust workflow improvement.