An ANSYS HFSS developer primarily works on the High Frequency Structure Simulator (HFSS) software, a electromagnetic (EM) simulation tool for designing and simulating high-frequency electronic products such as antennas, RF or microwave components, high-speed interconnects, and much more. They spend their time creating, testing, and refining simulation models, analyzing complex EM effects, and verifying design performance. They also collaborate with other engineers or clients to understand their needs and translate them into technical requirements. Their goal is to ensure the accuracy and reliability of the HFSS software in predicting the performance of high-frequency electronic designs.