An innovative and visionary scientist, instrumentalist and observer, Backer worked in many areas of astronomy and was involved in numerous ground-breaking projects over his 40-year career. His research focused on pulsars, high-energy astrophysics, the epoch of reionization and the exploration of these topics with the most imaginative and state-of-the art instrumentation.

Equally an expert in radio astronomy techniques and engineering instrumentation, Backer insisted that his work be considered within the main body of astronomy research, and not just as radio astronomy.