A . developer designs, builds, and maintains enterprise applications using Java Platform, Enterprise Edition .. They use technologies such as Servlets, JavaServer Pages, Enterprise JavaBeans, Java Message Service, and JDBC to develop scalable and reliable business solutions. They ensure the applications are compatible with different servers and databases. They work on debugging and troubleshooting issues, optimizing performance, and maintaining code quality. They may also be involved in designing and implementing application databases, user interfaces, and software testing. Additionally, they collaborate with other teams to integrate systems, ensuring seamless functionality.