Worked on stabilizing the AIX-specific asyncClose race test within the JetBrainsRuntime repository, focusing on improving CI reliability and test reproducibility. Addressed an intermittent failure by implementing a native method in C to detect pending signals support, integrating it with Java NIO to enable conditional thread signaling. This targeted fix allowed for the removal of the problematic test case from the problem list, reducing noise and churn in continuous integration runs. The work demonstrated a strong grasp of concurrency, native integration, and system programming, resulting in a more stable testing environment for JetBrainsRuntime on AIX platforms during the month.