A front-end developer builds and maintains the user-facing parts of websites or applications, utilizing languages like HTML, CSS, and JavaScript. They design and implement visual elements that users interact with, ensuring an engaging and responsive user experience. They also work closely with back-end developers to integrate the server-side applications. Other responsibilities include optimizing web pages for maximum efficiency and maintaining brand consistency throughout the design. They need to have a strong understanding of UX/UI design principles and be familiar with tools like AngularJS, ReactJS, or Vue.js. Accessibility and performance optimization are also crucial aspects of their role.