A MOSS (Microsoft Office SharePoint Server) developer designs and implements business solutions using SharePoint technologies. They create custom web parts, develop workflows and application pages, manage security and site content, and integrate SharePoint with other Microsoft products. Their role involves understanding business requirements, planning and designing SharePoint infrastructure, and troubleshooting issues. They also maintain the SharePoint environment, perform system updates, and ensure optimal performance. They work closely with other IT professionals to deliver user-friendly interfaces and improve business processes. MOSS developers are also responsible for providing technical support and training to end-users.