A professor at the Rhode Island School of Design, Hammett has a B.A. in Film from the London School of Film and Technique, a B.F.A. in Graphic Design from Ravensbourne College of Art and Design, and two masters degrees in Architecture and Graphic Design from Yale University.

He worked as a Senior Designer for Malcom Grear Designers, as Art Director for Wang Laboratories Inc. and as a consultant and designer for Compugraphic (AGFA) and Stratus Computer, Inc. before founding Sequel in 1984.