Hess began his career at Willis Towers Watson in 1989 and has held diverse leadership positions spanning business segment and geography roles. Prior to his current roles as President and CEO, Hess served as co-leader of North America at Willis Towers Watson and before that, managing director, the Americas, of Towers Watson. He served as the managing director of Towers Watson's Investment business since January 2010 and also worked in a variety of roles for over 20 years at Watson Wyatt, lastly as global practice director of Watson Wyatt's Investment business. Hess is a Fellow of the Society of Actuaries and the Conference of Consulting Actuaries, and a Chartered Enterprise Risk Analyst.

He has a B.A. cum laude in logic and language from Yale University.