Worked on the apache/gravitino repository to address a data integrity issue related to type conversion between Gravitino and Paimon catalogs. Focused on ensuring that nullability for list elements and map values was preserved during type conversion, the developer implemented a targeted bug fix using Java and data engineering techniques. This change reduced the risk of data inconsistencies when integrating with Paimon catalogs, supporting more reliable catalog integration workflows. The work was clearly documented with precise commit messages and linked to relevant issues, facilitating future maintenance and collaboration. No new features were added during this period, with efforts concentrated on robust bug resolution.