Wyllie, Jr. is Chairman Emeritus of the Board and Senior Principal at Degenkolb Engineers, and has over thirty years of professional experience in seismic evaluations, analysis, and design of strengthening measure for improved seismic performance. He served as a member of the California Council on Science and Technology, 1995-2000, Chairman of the State Historical Building Safety Board and was President of the Earthquake Engineering Research Institute. Wyllie is also an Honorary Member of the American Society of Civil Engineers and has been involved in over thirty projects in tunneling and shoring, and underpinning. He serves as consultant to several University of California campuses, various commercial and architectural clients, Department of Energy laboratories and many others. He was elected to the National Academy of Engineering in 1990 and served as Chair of the Civil Engineering section, 1999-2001.