Prior to his faculty appointment at the University, he was employed by Bank of China, Shandong as a senior software engineer and a director of IT department, from 1991 to 1999, and by MTU Library as a senior database administrator, from 2005 to 2007. Gao's areas of expertise are efficient algorithm designs, data management, systems security, and innovative HCI designs. Gao's research activities include exploring instruction level parallelism in superscalar processor designs; designing an innovative human computer interface by enabling one-handed eyes-free user input via tilting activities; vehicular ad-hoc network security and efficiency; and healthcare related network protocol designs and mobile computing. In addition to teaching graduate and undergraduate courses, Gao has supervised Senior Design student teams and served as a faculty member in PhD dissertation committee.