A GNSS (Global Navigation Satellite System) developer designs, implements, and manages software for satellite navigation systems like GPS, GLONASS, Galileo, or BeiDou. They work on algorithms for positioning and timing, ensuring accuracy and reliability. They handle the integration of GNSS with other technologies like GIS or IoT, and may also work on signal processing. Their duties include debugging, testing, and improving these systems. They also need to stay updated with the latest developments in satellite technology and navigation systems. These developers often work for tech companies, defense contractors, or government agencies.