A Citrix Xen Server and Desktop developer designs, implements, and maintains server and desktop virtualization solutions using Citrix technologies. They are responsible for creating scalable virtual environments, ensuring high availability of systems, and troubleshooting any issues that may arise. They work on both server-side (XenServer) and client-side (XenDesktop) to provide remote access to desktops and applications. They also ensure system security by implementing policies and procedures. Additionally, they may provide technical support, conduct performance tests, and collaborate with other teams to integrate Citrix solutions with other software. Their role plays a critical part in enhancing business continuity and flexibility.