Khush Gupta focused on enhancing distributed query reliability in the apache/solr repository by addressing a bug affecting cross-collection joins. Leveraging expertise in Java and Apache Solr, Khush implemented a fix ensuring that the shards.preference parameter is correctly honored during cross-collection queries, allowing user-specified routing preferences to propagate to query parameters and direct requests to appropriate replicas. The solution included comprehensive end-to-end test coverage to validate routing correctness and prevent regressions under high-load scenarios. This targeted backend development improved routing accuracy and stability, reducing misrouting for distributed workloads and contributing to more predictable performance for Solr users with explicit routing needs.