During February 2026, Liu Lietong focused on backend stability for the apache/paimon repository, addressing a subtle but impactful bug in the record comparator code generation path. Liu identified that the cache key for record comparators did not account for sort order, which could cause ascending and descending comparators to share the same cached class and result in incorrect sorting. By updating the cache key to include sort order and adding regression tests for both ascending and descending behaviors, Liu improved the reliability of paimon’s sorting semantics. This work leveraged Java, backend development expertise, and unit testing to enhance code predictability.