During February 2026, Shifan Li focused on stabilizing the Hadoop test suite within the apache/hadoop repository by addressing reliability issues across multiple components. He consolidated four targeted fixes to reduce test flakiness, eliminate race conditions, and resolve deadlocks affecting MapReduce, YARN, and HDFS modules. Using Java and leveraging his expertise in test automation and concurrency handling, Shifan improved the reliability of thread dumps, health threshold monitoring, RMHA, and DFSAdmin tests. These changes enhanced continuous integration stability, enabling faster and safer validation of critical Hadoop components. His work demonstrated depth in diagnosing and resolving complex, concurrency-related software testing challenges.