In the first edition of 101 Careers in Mathematics, I wrote about my switch from mathematics to applied mathematics, specifically operations research, a field that uses mathematics to model complex systems and optimize their design. I taught courses in operations research at Boston University in the College of Engineering. I later worked at engineering consulting companies applying operations research techniques to real-world problems. My job at the time of the first edition was at MIT Lincoln Laboratory working on algorithms for air traffic control automation systems.

Since that time, I have not only changed jobs twice, but also changed careers. When I explored potential jobs outside the Lab, I kept hitting a job barrier because I had no recent software experience, which most job opportunities required. Although I had done some FORTRAN programming earlier in my career, I had no experience with modern languages such as C, C++, and Java. Fortunately, a friend of mine was working at a start-up software company that offered an intern program. Even though the program was designed for students who were finishing computer science degrees, my friend convinced the company to hire me. I was assigned a mentor, who directed my professional development in software engineering. Six months later, I graduated from intern to permanent staff. For the next two years, I worked on consulting projects for the government involving client/server architextures.

I also developed and taught a training course in distributed object computing with Java.