Wyman Ford is a private investigator.
For many years prior to the start of the series, Ford was a CIA operative and a very good one by all accounts. His wife was also with the Firm and they made a fine pair, working in various countries around the globe and, from the sound of it, having a terrific time. That ended when an incident in Cambodia took her life and took Ford's will to live or do anything else.
After a severe bout of depression, Ford, a devout Catholic, visited a Benedictine monastery in the southwestern U.S., staying there for a couple of years. An matter that came up during his time with the Brothers is told in the first adventure and after it was over and he felt able to get on with his life, he chose his new profession.
As private eyes go, or CIA agents for that matter, Ford has to rank pretty high up on the educational charts. As we learn early in the second adventure, and the first one to have him as the main character, Ford obtained a B.A. in anthropology from Harvard, not an easy task. He then went on to earn a Masters in Computer Sciences from nearby M.I.T. and completed his schooling with a doctorate in cybernetics. His expertise in cryptology and computers is without question.
His cases fall very much into the sort of work he likely might have done had he continued with the CIA though they come to him from quite different directions, the primary one being the science advisor to the American President. This man, Stanton Lockwood III, is an important man in America's capital and not adverse to the idea of becoming more important. The cases he sends Ford all seem relatively dull to the advisor but do not turn out that way.
The adventures detailed in the books all revolve around the jobs handed him by Lockwood but a year or two fall between each and from the sound of things, Ford's work during that time has not been light but apparently nowhere near as dangerous and challenging. Likely that is why, despite Ford's uttered wishes the assignments not "be like the last one", he does not hesitate to answer the call.