While other bankers fretted about foreclosures and defaults this year, Avid Modjtabai spent her days (and a few nights) worrying about ATMs. Twelve thousand of them, to be exact, along with 58,000 servers, which store 21 million gigabytes of data and process 6.3 million checks each year. That's what it means to be the head of technology and operations at Wells Fargo & Co. as it digests behemoth Wachovia Bank and cements its position as the country's fourth-largest financial institution.

"Clearly it's a huge effort," says Modjtabai, pointing out that the merger doubled Wells' asset size, to $1.3 trillion, and that the combined institution now processes 15 billion customer transactions every year, all of which go through her department. "But when it's very challenging is also when it's very interesting."

Sometimes the biggest challenges seem very mundane, and some refer to Modjtabai's business as the "plumbing and wiring" of the bank. Take e-mail, for example. When Wells Fargo and Wachovia merged, they were operating on two different systems - IBM's Lotus Notes and Microsoft Outlook - which caused countless snags when it came to sharing contacts and creating calendar entries. Bringing 280,000 employees on the same system, without causing outages that could disrupt customer service turned out to be a huge expense and logistical headache. Still, Modjtabai surveyed her team, took their recommendations and is now spearheading one of the largest email convergences in financial history.

"At the end of the day we are problem solvers," says Modjtabai, who left her native Iran in 1979 to study engineering at Stanford University. "My approach is very fact-based. When we are coming up with long-term solutions for our network infrastructure, I look at the facts on the table and never lose my focus on the customers."

This attitude has served Modjtabai well in her career. Since joining Wells Fargo in 1993 as a corporate strategy consultant, Modjtabai has been dispatched to a wide variety of divisions at the bank, including running human resources. The universe under her oversight has also grown quickly: she now manages a $5.1 billion budget and 28,000 employees. Observers often point out that her ascent looks like a test run for a C-level spot, but John Stumpf, Wells Fargo's CEO, wouldn't corroborate the speculation.

"We have a very robust talent review process here," he says. "Avid has a wonderful future here and so do a lot of people."

Of course, Stumpf is thrilled with her performance so far. In addition to her role has head of human resources, Modjtabai also led the Internet Services Group from 2002 to 2005, helping the bank become one of the most respected providers of online financial services.

Stumpf attributes her success in large part to her knack for cutting to the core of a problem and working with others in finding a solution.

"Making the complex comprehensible is one of her unusual skills," he says. "She's also one of the best collaborators I've ever seen."

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