An AnimateCSS developer is a professional who utilizes the AnimateCSS library to create stunning visuals and animations on websites. They integrate this CSS library into web development projects to enhance user interfaces and improve user experience. Tasks include developing interactive elements, adding transitions and transformations, and designing dynamic web pages. They may also test and debug animations, ensuring they function correctly across different browsers and devices. Additionally, they may work closely with UX/UI designers and front-end developers to ensure the animations align with the overall design and functionality of the website.