Pioneer in modern software engineering, Constantine began his professional career in computers with a summer job at Scientific Computing, at the time a subsidiary of Control Data Corporation, in Minneapolis, having learned programming at the Massachusetts Institute of Technology. He went on to full-time work at MIT's Laboratory for Nuclear Science, where he wrote routines for analyzing spark chamber photographs, and then to C-E-I-R, Inc., where he worked on economics simulations, business applications, project management tools, and programming languages.
While still an undergraduate at MIT, Constantine began work on what was to become structured design, formed his first consulting company, and taught in a postgraduate program at the University of Pennsylvania Wharton School. The core of structured design, including structure charts and coupling and cohesion metrics, was substantially complete by 1968, when it was presented at the National Symposium on Modular Programming. He joined the faculty of IBM's Systems Research Institute the same year, where he taught for four years and further refined his concepts.
