A JSP (Java Server Pages) developer designs and implements web-based applications using Java technologies. Their responsibilities include writing and maintaining Java code, developing JSP pages, and integrating applications with databases. They also work on server-side programming to generate dynamic web content, troubleshoot issues, and ensure optimal performance of web applications. They collaborate with the design team to establish the look and functionality of websites, and with other developers to integrate backend systems. In addition, they test their codes for bugs and fix any issues that arise. They may also be involved in software analysis, code reviews, and application updates.