Worked on core memory management and object identity improvements across the symfony/symfony, symfony/http-kernel, symfony/serializer, and doctrine/persistence repositories. Introduced a WeakMap-based registry in Doctrine DBAL PostgreSQL store to enable garbage collection and reduce memory leaks, and standardized object identification by replacing spl_object_hash() with spl_object_id() throughout Symfony components. Enhanced error tracking and circular reference handling by improving the reliability of exception object identification in LoggerDataCollector and AbstractNormalizer. Focused on backend development and code refactoring using PHP, with an emphasis on memory management, object-oriented programming, and database management to improve reliability and maintainability of core systems.