A GeoServer developer is responsible for designing, implementing, and managing geospatial data services using GeoServer software. Their work involves setting up spatial data infrastructures, integrating geospatial data from various sources, and developing web services for data distribution. They ensure that geospatial data is available, accurate, and accessible for GIS applications. They also troubleshoot and resolve issues related to GeoServer operations. Additionally, they may customize GeoServer functionalities to meet specific requirements, and constantly optimize the system for better performance. Their role is crucial in domains like urban planning, environment monitoring, and transportation where geospatial data is extensively used.