A JavaScript (JS) Developer designs, tests, and implements web applications using JavaScript programming language. They create innovative solutions to web design issues to improve website functionality and user experience. They work closely with clients or company management to develop project specifications and make adjustments based on feedback. They also collaborate with other developers to integrate different technologies into web design, such as HTML, CSS, and server-side languages. They often use frameworks like React or Vue.js for front-end development, and Node.js for back-end. They debug and troubleshoot software issues, and stay updated with latest industry trends.