A web developer writes code in languages such as HTML, CSS, XML, and JavaScript to build a website’s structure, design, and functionality. They also work closely with web designers to match the visual design of a site with the technical back end. Web developers may work on various websites, such as e-commerce sites, social media platforms, and company portals. Overall, the main goal of a web developer is to develop and maintain a website whilst ensuring that it’s fast, responsive, and simple for users.