A JavaScript Developer specializes in using JavaScript to build dynamic and interactive web applications. They are skilled in both client-side and server-side development, using JavaScript frameworks and libraries such as React, Angular, Vue.js, Node.js, and Express to create responsive and scalable web applications. JavaScript Developers work with HTML, CSS, and APIs to enhance user interfaces, optimize web performance, and implement features like form validation, real-time updates, and interactive elements. They are also proficient in debugging, testing, and optimizing JavaScript code for compatibility across different browsers and devices. Their goal is to create seamless, engaging web experiences that meet both user needs and business objectives.