A Jenkins developer is responsible for setting up, configuring, and managing continuous integration and continuous deployment (CI/CD) pipelines using Jenkins software. They create automated build and deployment scripts, monitor pipeline processes, and troubleshoot any issues that arise. They collaborate with software developers to ensure seamless software delivery, from integration and testing phases to final deployment. They also maintain the Jenkins environment, perform upgrades, and ensure its security. Furthermore, they often need to customize Jenkins as per project requirements, which involves creating and managing plugins. The role requires expertise in scripting languages, version control systems, and software development lifecycle.