A GDAL developer works with the Geospatial Data Abstraction Library (GDAL), a translator library for raster and vector geospatial data formats. Their role involves creating, converting, processing, and analyzing geospatial data to develop applications or services. They use GDAL's functionalities to handle geospatial data in various formats including GeoTIFF, PNG, and JPEG. They might also manipulate these data for tasks such as georeferencing, warping, or transformations between coordinate systems. As part of their responsibilities, they may deal with troubleshooting and optimizing the performance of applications using GDAL, while ensuring data integrity and accuracy.