A GIS software developer designs, tests, and implements Geographic Information Systems applications. They work with geospatial data to create software that can be used for mapping, data analysis, and strategic planning. Their responsibilities include programming, database management, and troubleshooting. They collaborate with scientists, engineers, and other professionals to understand their needs and develop appropriate solutions. They are also responsible for maintaining and updating GIS systems, ensuring data accuracy, and providing technical support. Furthermore, they utilize programming languages like Python or Java, and GIS tools such as ArcGIS or QGIS. They also create user-friendly interfaces and documentation.