Panagiotis Garefalakis contributed to the apache/incubator-gluten repository by updating the CI test infrastructure to support Spark 3.5 compatibility for Velox Enhanced tests. He achieved this by modifying the GitHub Actions workflow, ensuring that the SPARK_HOME environment variable pointed to the Spark 3.5 installation directory. This change aligned the test environment with the latest supported Spark runtime, reducing compatibility drift and streamlining validation for new releases. His work focused on CI/CD and configuration management, utilizing YAML to define and manage workflow updates. The depth of the contribution lies in its targeted scope and its impact on reliable, version-aligned testing.