Tillerson began his career as a civil engineer with Exxon in 1975 after graduating with a bachelor's degree in civil engineering from the University of Texas at Austin. By 1989 he had become general manager of the Exxon USA central production division. In 1995 he became president of Exxon Yemen Inc. and Esso Exploration and Production Khorat Inc. In 2006 Tillerson was elected chair and chief executive of Exxon, the world's sixth-largest company by revenue. Tillerson retired from Exxon effective January 1, 2017. He is a member of the National Academy of Engineering.