March 2026 (apache/incubator-gluten) monthly summary focusing on key accomplishments, bug fixes, and business impact. Highlights include Spark 4.x compatibility test suite enablement, stability fixes, and test infrastructure improvements. This period delivered expanded coverage for Spark 4.x runtimes, improved exception handling between Velox and Spark, and encoding/test environment hardening to ensure reliable CI results.

February 2026 focused on stabilizing Gluten on Spark 4.x, expanding testing coverage, and delivering substantial build, tooling, and Velox integration improvements to accelerate development and reduce upgrade risk. Key progress includes Spark 4.x compatibility testing enhancements for Gluten, targeted fixes to LeftSingle join handling, and added suites to exercise XML expressions and deprecated Spark aggregators tests. Velox Delta Lake test compatibility was updated to Delta Lake 3.3 APIs to prevent breakage in production pipelines. Build system and developer tooling were overhauled to speed up iteration (incremental builds, protobuf and Scala tooling upgrades, consolidated build-info, new dev scripts, and Maven Daemon support). Reliability and CI stability were improved through test script fixes (Arrow memory init), and restoring a robust Scala build default with a fast-build profile. These changes deliver clear business value by enabling safer Spark upgrades, faster feedback loops, and more reliable test and build infra while showcasing broad technical breadth across Spark, Gluten, Delta Lake, Velox, and build tooling.

January 2026 monthly summary focusing on key features delivered, major bugs fixed, and overall impact. Highlights include partitioning-aware union for ColumnarUnionExec delivering preserved partition semantics and improved efficiency, plus Spark 4.1 readiness work with internal build/test improvements and test workflow cleanups. Also completed Gluten Spark 4.1 test suite integration and upgraded Spark 4.1.0 to 4.1.1, alongside a stability fix for memory tests to reduce flakiness. These efforts increase correctness, performance, and reliability, enabling smoother Spark integrations and faster validation cycles.

December 2025 performance summary: Delivered cross-version Spark compatibility layer for StructsToJson and StaticInvoke, extended geospatial type support with Spark 4.1 compatibility, hardened test infrastructure for Spark 4.x, and improved shuffle ID extraction integration with Gluten to support adaptive plans. These efforts broaden product compatibility, reduce flaky tests, and boost reliability and developer productivity, enabling broader adoption and faster iteration.