During January 2026, Shijie Yang developed foundational Python UDF, UDAF, and UDTF support for the apache/doris repository, enabling extensible SQL processing with custom Python logic. He architected a production-grade Python execution path using Arrow Flight RPC and managed multi-version Python environments with conda and venv, allowing flexible deployment. Yang integrated Snowflake-style UDAF state management and UDTF table functions into Doris’s vectorized engine, achieving 3-10x speedups in Pandas and Arrow modes. His work included robust process pool management, health checks, and auto-recovery for Python workers, with comprehensive testing and documentation, demonstrating depth in C++, Python, and software architecture.