A developer specializes in using the framework, a responsive front-end framework that allows for the creation of elegant, flexible, and responsive websites and applications. They design and implement user interfaces, ensuring optimal performance across various devices and screen sizes. Their tasks include coding, testing, debugging, and integrating new features or improvements, often using HTML, CSS, and JavaScript. They also collaborate with other team members, such as designers and back-end developers, to deliver a seamless user experience. Their work involves problem-solving, innovation, and keeping up-to-date with the latest industry trends and technologies.