Jana Baker is an agent with the FBI.
Her membership in a compendium devoted to more cloak and dagger sorts comes from her work and expertise in fighting the ever-present and, unfortunately, often sophisticated world of terrorism. While most of her targets are located in the Middle East, through technology, the perpetrators can and do work anywhere.
Baker came to this line of work indirectly in that her first real job in her expertise of accounting was with a major player in computer technology, the prestigious Petrolsoft. It was actually just an internship but it was a prize achievement and one she had definitely earned. She graduated second in her class in college, maintaining her impressive GPA while also holding the position of captain in her track team. Her ultimate goal was to "be involved in international stock trading" and her internship was just the first rung in the ladder she had to climb.
She could not have expected or known that she would not rise any higher. Getting a job with a company who was secretly working with terrorists can have a deleterious effect on a planned career. When she agreed when asked to help prove her employer was dirty, she in effect made a strange lateral move, ending up using her accounting skills with the FBI fighting other terrorist organizations.
Baker has a very impressive brain housed in the quite attractive, athletic body. She also has a lot of drive to have achieved what she has. It would have been easy to just stay on the farm in Tennessee where she was raised by her grandparents but she knew from the time she became a teenager that her destiny lay elsewhere, as much as she loved it there. She could never have imagined that instead of a future in business, working as a stock trader, it would include fighting some very nasty enemies of her country, and acquiring one especially powerful and dedicated nemesis.