During December 2024, Kaiqi Jin focused on improving data pipeline reliability by addressing a critical bug in the xupefei/delta repository. He enhanced the Delta-to-Iceberg conversion process by implementing logic in Scala and Spark to assign a default partition value when entries are missing, thereby preventing failures during partitioned data migrations. This change strengthened the robustness of migration workflows without altering user-facing behavior, aligning with ongoing reliability goals. Kaiqi ensured all existing tests continued to pass, minimizing regression risk and maintaining test coverage. His work demonstrated depth in data engineering, particularly with Delta Lake and Iceberg, through targeted, maintainable improvements.