Martina Hund-Mejean signed on as MasterCard's CFO in November 2007, just before the financial crisis unfolded and a year and a half after the payments company's IPO. Hund-Mejean had served as treasurer at Tyco and Lucent Technologies, after working in finance at General Motors. As financial markets melted down in 2008, MasterCard aggressively cut its operating costs, she explains, noting that "nobody should waste a good crisis." Hund-Mejean says the Purchase, N.Y.-based company has applied the budgetary discipline that's common among manufacturing companies to its financial services model. She also talks about the evolving role of MasterCard's finance department.

T&R: How did the financial crisis impact MasterCard's long-term strategy?

Hund-Mejean: We took the discipline our business units learned during the crisis and applied it to what we do in our base spending and new investments. When we give people budgets now, they don't just think about how that budget can be spent. Rather, they ask whether they really need to use the entire budget, and whether some things can be done less expensively and money actually returned to their business units or corporate, so it can be spent on other projects.