During July 2025, Jun Seok Heo focused on enhancing data integrity and stability in the crossoverJie/starrocks repository by addressing a critical bug in the Segment Iterator pruning logic. Working primarily in C++, he resolved an issue where pruned columns did not maintain size consistency with unpruned columns during filtered-column processing. By ensuring that pruned columns are resized to match the first unpruned column, Jun Seok improved the reliability of segment reads and reduced edge-case failures related to columnar storage. His targeted bug fix demonstrated a strong understanding of data integrity and contributed to the maintainability of the codebase.