Worked on enhancing the robustness of theme JSON resolution in WordPress by introducing WP_Post validation within the Theme_JSON_Resolver, addressing a recurring source of runtime errors. This improvement, implemented in both the peterwilsoncc/wordpress-develop and WordPress/WordPress repositories, ensured that only valid WP_Post instances are processed, thereby increasing the reliability of theme processing across core and forks. Leveraging PHP and modern WordPress development practices, the work included a core version bump and resolved issue #64434. The changes reduced support overhead and improved user experience by preventing errors during theme JSON handling, demonstrating careful attention to code quality and cross-repository collaboration.