After earning his master's degree in 1962, David spent 27 years with IBM, most of which was in the technical library and subsequently the Competitive Resource Center. He then went to EDS, the company founded by Ross Perot, for nearly 10 years and retired in 2005. He celebrated his 80th birthday on July 22, 2019.

He continues to do volunteer work at Baylor Hospital in Irving, Texas, where he demonstrates a hospital-owned robot for patients, staff and visitors, and plays his Lyon and Healy Troubadour harp. The hospital recently awarded him its "Five Star Spirit Award" for his work.