During October 2024, Mingkang Li focused on improving reliability in Spark’s backend exception handling within the xupefei/spark repository. He addressed a critical bug in the SparkUncaughtExceptionHandler by enhancing its logic to traverse the exception chain and accurately identify fatal errors, such as OutOfMemoryError, which were previously misreported as uncaught exceptions. This Scala-based solution ensured that Spark applications now report precise exit codes, improving shutdown semantics and production observability. Mingkang applied his expertise in Spark, backend development, and exception handling to deliver a targeted fix that deepened the robustness of error reporting for Spark deployments without introducing new features.