Rob Reeg took over as president of MasterCard's Global Technology and Operations in May 2008, the de facto chief of IT at the US$4 billion credit-card and electronic payment provider.

This is a glimpse into his new world: On behalf of 25,000 financial institutions, MasterCard's worldwide network in 2007 processed 18.7 billion transactions totaling some US$2.3 trillion. On an hourly basis, the network has to manage 140 million transactions, with a response time of 140 milliseconds per transaction. And 99.999 per cent network availability is standard operating procedure.

All of this wasn't totally new to Reeg. He had served in the position on an interim basis since January 2008. And before that he was MasterCard's CTO. "So it was a fairly easy transition," he says.

Though the transition may have been a piece of cake, his job's demands are anything but. Ridiculous network requirements aside, Reeg is responsible for managing MasterCard's global IT environment, headquartered in the US and with operations in 210 countries, preventing frauds and credit-card scams, innovating with transaction-processing systems and enhancing financial institutions' product offerings gleaned from MasterCard's data warehouse.

Thomas Wailgum talked to Reeg about his biggest worries, how his credit-card data got compromised, and just how "Priceless" his IT staff is.

What are your new responsibilities?

There are five key functions I'm focused on: 1. Our global network and how those 18.7 billion transactions flow. 2. Making sure we leverage that network to provide very fast, reliable payment processing. 3. On top of that platform, how do we provide our customers with custom and differentiated payment solutions. 4. How do we provide support to customers as they use our products and services. 5. How do we leverage that gold mine of data that occurs when you have 18.7 billion transactions that you're processing.

Who are MasterCard's customers?

Our customers are typically the banks. We're in what we call a four party model. There are card holders, who have a relationship with an issuing bank; so that's two parties in the model. On other side there are the merchants have a relationship with their bank, an acquiring bank. Those are the four primary stakeholders in any kind of payment transaction.

We sit in the middle, between the issuing and acquiring banks, making sure those payments occur as they should and then move the money appropriately.

How big of an infrastructure do you have to support and maintain? It must be huge.

Actually from a pure server footprint standpoint, in the data center, we probably have fewer actual footprint servers because of techniques like virtualization that help us leverage one box to do multiple things.

Where it gets interesting is philosophically: We try to put [transaction] processing as close to our customers, the banks, as possible. When we talk about the global network, we have small servers that sit with the bank customers that connect to our network. What it does is it gives us intelligence there at the end of the network. So as a transaction comes through, we can take a look at that transaction and decide how do we best process that transaction for the benefit of all those four parties in the model.

As to processing, the majority of transactions we're looking at relate to how do we process them as fast as possible in the most accurate way. The way to do that is by peer to peer: If you're using your card in Europe, in London, say, and you swipe your card as you check out of hotel, we can route that transaction to the hotel's acquiring bank in London directly to your issuing bank and get that message back for approval without ever going through St. Louis or some big data center in the middle of all that.