...front-office transformation with a new internet bank - now live with 300,000 members, according to Prestedge. Migration will ramp up this month, to ensure all 4.5 million accounts are migrated to the new internet bank by the end of November.
The front-office transformation programme will also include new applications in call centres and branches - so Nationwide has a fully integrated sales applications stack, says Prestedge. "I expect that after the internet bank being live and stable we will start the programme of deployment of those applications into our other channels early 2013," he adds.
Add to that, the company is also replacing its payments platform - live already for faster payments. By the end of this year, Nationwide will have real-time financial transactions across all of its customer base, says Prestedge, and will be making those payments platforms integrate with SAP in the first half of next year.
Ahead of it, there's much more to come - not least a whole cloud computing strategy to be shaped now that Nationwide has the infrastructure in place to support it. "Having built the infrastructure to be resilient, what we are now doing is thinking through how we leverage cloud computing and what is our appetite for third-party hosted apps," he notes.
"I have a strong view that you enter into the world of cloud only once you're really sure that your own infrastructure estate is resilient, well architected and understood, because then you understand the risks you're taking. And for a business that's as highly regulated as banking, you can understand the decisions in the context of the regulatory environment.
"Until I had the new datacentres live at the back end of last year and the infrastructure estate largely virtualised, it would have been an exercise in theory," Prestedge adds.
There's also the technical integration of the acquired building societies - to put them on a common apps platform with the rest of Nationwide's business. This is on ice until 2013-14, after the banking and savings programme is fully delivered. "As you can imagine, I don't want to decommission their apps, put them onto Unisys and then take them off Unisys [to put them on SAP]," says Prestedge.
Mobile is also an area where Nationwide is looking to develop, says Prestedge, adding: "The internet revolution took a very long time to happen; the mobile revolution will happen at a pace that I believe will surprise all of us."
The building society is probably a third of the way through the transformation it kicked off in 2008, according to Prestedge - which, while originally slated as a five-year programme, is now described as "multiyear". So what would he have done differently if he could turn the clock back to 2008?
"If I had my time again...