Deason grew up on a farm near Rogers, Arkansas. He moved to Tulsa, Oklahoma after graduating from high school, and he got a job at Gulf Oil. Deason got a job for a data processing company, and eventually took control of a struggling Dallas company that he renamed MTech. After selling MTech, Deason founded Affiliated Computer Services in 1988. ACS became one of the first companies to outsource office work to places outside of the United States. The company went public in 1994. Deason retired as CEO of the company in 1999, but remained chairman.