During April 2025, this developer focused on backend engineering within the apache/incubator-gluten repository, addressing a complex bug in the Gluten query engine’s aggregate expression handling. By refining the rewriteAggregateExpression logic in Java and Scala, they ensured that expressions were no longer extracted for Partial or Complete aggregation modes, which previously led to invalid reference bindings in ProjectExecTransformer. This targeted fix improved the correctness and stability of query plan generation, reducing runtime errors and support overhead for analytics workloads. Their work demonstrated a deep understanding of distributed systems, query optimization, and SQL semantics, contributing to more reliable production deployments.