A JavaServer Pages (JSP) developer designs and builds dynamic web applications and services using JSP technology. They write server-side scripts, integrate back-end Java code, and create user interfaces. They also manage databases, handle client-server communication, and ensure web security. They work closely with clients to understand their requirements and provide solutions. Debugging, testing, and improving application performance are also part of their duties. They often work in teams with other software developers, collaborating on larger projects, and are expected to keep up-to-date with the latest technological developments in the field of web and software development.