Worked on core WordPress development, focusing on refining image export formatting within the wordpress-develop repository. Addressed a key feature by refactoring the wp_get_image_editor_output_format function, improving variable naming and updating documentation to clarify HEIC and HEIF image handling. Fixed two bugs, including correcting variable naming in wp_check_filetype_and_ext for accurate HEIC processing and resolving JavaScript logic on the old Edit Post screen to ensure proper category and sub-category selection. Utilized PHP, JavaScript, and jQuery to enhance both backend and frontend code quality, emphasizing maintainability, documentation accuracy, and improved user experience across WordPress core repositories.