Worked on the neos/neos-ui repository to deliver a major upgrade of the CKEditor 5 editor, focusing on enhancing editing capabilities and developer efficiency. Upgraded CKEditor 5 from version 16.0.0 to 44.0.0, which required adapting the application’s JavaScript and CSS codebase for compatibility with the new editor APIs and updated plugin ecosystem. Stabilized and updated end-to-end tests using TestCafe to ensure reliable integration and continuous feedback in CI pipelines. This work improved the overall editing experience and productivity for users, while aligning the frontend code and tests with the latest standards in modern JavaScript-based editor development.