During June 2025, this developer contributed to the apache/lucene repository by designing and implementing the ParentsChildrenBlockJoinQuery feature using Java. The work focused on optimizing search and indexing by enabling efficient filtering of parent and child documents within the same block in a single pass, which reduced cross-join overhead and improved data locality. The implementation supported parent and child queries, parent filters, and configurable child limits per parent, addressing both performance and scalability. Comprehensive unit testing was included to validate functionality, edge cases, and concurrency constraints, demonstrating a strong emphasis on reliability, query optimization, and robust Java development practices.