A CSS JavaScript developer is a web professional who designs and implements user interface for applications using front-end technologies like CSS (Cascading Style Sheets) and JavaScript. They create visually appealing sites with user-friendly design and clear navigation. They work on the layout, appearance, and in some cases, content of a website. Their role involves writing web design programs in languages such as HTML and CSS, and enhancing website interactivity with JavaScript. They also ensure websites are optimized for speed and scale, troubleshoot and debug issues, and maintain and improve websites. They often collaborate with back-end developers and web designers.