Worked on improving the reliability of the vfio async event handling test suite in the amzn/rdma-core repository. Addressed a persistent race condition by implementing cross-thread synchronization using waiting loops, ensuring that event registration completed before events were triggered. This approach reduced test flakiness and increased the correctness of system testing, supporting safer release cycles and more predictable development. Leveraged Python to manage concurrency and event handling, focusing on robust testing practices. The work resulted in a more stable test environment, allowing for greater confidence in future changes to VFIO async event handling and contributing to overall codebase quality.