A Java Web Server developer designs, implements, and maintains server-side web application logic. They use Java technologies to develop web applications, services, and interfaces. They work with web designers to integrate user-facing elements with server-side logic, ensuring functionality and efficiency. They also manage data storage solutions, troubleshoot applications and services, and optimize the server's performance. They ensure application scalability and security, and often collaborate with other team members in the software development lifecycle, including testing and deployment. They must also stay updated on new technologies and programming languages relevant to their field.