Worked on enhancing the Symfony FrameworkBundle by improving the stability of the test lifecycle, specifically addressing kernel resource management during PHPUnit test runs. Introduced a mechanism to ensure the kernel shuts down after all tests in a class by implementing an ensureKernelShutdown call within KernelTestCase::tearDownAfterClass and refactoring it as an AfterClass attribute. This approach reduced kernel leaks and improved test isolation, leading to more reliable and faster continuous integration runs. The work, contributed to the symfony/symfony repository, demonstrated expertise in PHP, framework development, and automated testing, with a focus on robust CI processes and resource efficiency.