Efstratios Giak focused on enhancing test coverage for complex native queries in the hibernate/hibernate-orm repository during February 2026. He developed a dedicated test class in Java, leveraging Hibernate and JPA, to validate entity mappings that use join formulas and computed fields. His work included creating tests for retrieving comments and posts with specific join conditions, addressing the risk of regressions in scenarios involving intricate relationships. By extending unit testing to these advanced query patterns, Efstratios improved the reliability of ORM behavior when handling native queries. The depth of his contribution lay in targeting nuanced aspects of entity result validation.