A fuel cell engineer's job duties and responsibilities revolve around the design of fuel cell components or systems for a variety of applications. Fuel cell engineers design and develop fuel cell components for mechanical and electromechanical modules. In this job, you work from start to finish on these systems, from fabrication to the test and debug stage, to assembly and manipulation of the system. This creates high-quality designs that allow fuel cells or a generator to work more efficiently and with different fuel sources. A fuel cell engineer may work with a technician or act as his or her own throughout the process of building, manipulating, and rebuilding the fuel cell.