During their two-month tenure, MSL Fulong focused on critical bug fixes in large-scale C++ data processing systems. Working within the IBM/velox and facebookincubator/velox repositories, they addressed correctness issues in aggregate result handling under GCC 11 -O2 optimizations by introducing temporary buffering, which improved stability and reliability in optimized builds. In another instance, they enhanced Velox’s Parquet row group filtering by ensuring string statistics from older parquet-mr versions were ignored, preventing incorrect query results due to signed-byte ordering. Their work demonstrated strong debugging and unit testing skills, delivering targeted, high-impact improvements to production data processing pipelines without introducing new features.