A Light JS/JQuery developer is responsible for designing, implementing, and managing web applications using JavaScript and JQuery, lightweight programming languages primarily used for enhancing interactivity within websites. Their duties include creating user-friendly web pages, optimizing applications for maximum speed and scalability, ensuring high performance on both mobile and desktop, and implementing responsive design for mobile sites. They may also be involved in troubleshooting bugs, maintaining code quality, and collaborating with other team members to ensure seamless user experience. They must stay updated with the latest industry trends and technological advancements.