During July 2025, Dae-Gyu Han focused on improving test reliability and memory safety in the spring-projects/spring-boot repository. He addressed a bug in the ExampleAdditionalConfig test by replacing ThreadLocal.set(null) with ThreadLocal.remove() in SpringApplicationTests.java, ensuring proper cleanup of thread-local variables. This Java-based solution targeted the prevention of memory leaks and reduced flaky behavior in multithreaded test environments. By aligning with best practices for managing thread-local state, Dae-Gyu’s work enhanced the stability of the test suite and supported faster, more stable releases. His contributions demonstrated attention to detail in Java testing and thread management within Spring Boot.