A Java Servlet Developer creates dynamic web applications using the Java Servlet API. Their responsibilities include designing, coding, and deploying server-side logic to handle HTTP requests and responses, managing session data, and integrating with databases or web services. They also ensure the servlet is compatible with different servers like Apache Tomcat or Jetty. They may work on user authentication, form data processing, and web page construction. Furthermore, they must ensure robustness, efficiency, and scalability of the servlet, following best coding practices. They often collaborate with front-end developers, integrating their servlets with the user interface.