In March 2026, Biruk Tesfaye focused on backend reliability within the apache/spark repository, addressing a race condition in Spark Connect that could cause query events to be lost if a session closed during execution. Using Scala and leveraging expertise in Apache Spark, Biruk engineered a solution that ensures terminal events are reliably posted even when sessions end abruptly, preventing silent failures and lingering query states. The work included developing targeted unit tests to validate event delivery under interrupted workloads, demonstrating a deep understanding of distributed system robustness and event handling. This fix improved stability for users running interactive or long-running queries.