Intuit is defying common industry wisdom that enterprises should spread their bets among multiple vendors to avoid lock-in. Intuit is going all-in on Amazon, noting that the hypothetical cost of switching later is better than the immediate, real cost of managing connectivity to multiple cloud platforms.

Intuit Inc. (Nasdaq: INTU) is moving 100% of its infrastructure from its own data centers to Amazon Web Services Inc. to improve developer speed, delivering products faster and across more devices. The company is also moving its internal applications to the cloud.

"In the cloud, you can spin up and down a test environment and move a lot faster," says Tayloe Stansbury, executive VP and CTO for Intuit. Stansbury presented at last month's Open Networking User Group conference, conveniently located (for him) at Intuit's Mountain View, Calif., headquarters, and spoke with Light Reading one-on-one after his presentation.

Intuit started working with Amazon in 2010, with a tool for TurboTax called AnswerXchange, and has since moved more than 50 apps to AWS, with plans to move the rest of its applications to AWS over the next few years.

Intuit had more than 30 data centers at its peak, down to two today in the US, with a handful of regional data centers outside the US, and other data centers inherited with corporate acquisitions. The plan is to phase out all of its own data centers, on a timetable that Intuit isn't publicly sharing.

The cloud migration is a step in a three-decade journey that began when Intuit was founded in 1983, providing Quicken financial software for MS-DOS PCs. In the late 1990s, Intuit became a software-as-a-service (SaaS) provider (before that became a catchphrase), providing financial services over dial-up Internet.

"That was still a minority of the business at that point. It didn't become the majority until within the last ten years," Stansbury says.

Intuit's different business units "made their own way to cloud," with proliferating data centers, hardware and software systems, Stansbury says.

Starting about seven years ago, Intuit decided to consolidate to achieve high availability, disaster recovery and high performance. Availability and security are its top priorities.

"This is a company that has reinvented itself multiple times over the course of 33 years," Stansbury said. "Innovation is the core of who we are and who we aspire to be."

Though speed-to-market is the main benefit for moving to the cloud, elasticity is also a plus. "Many of our servers gather dust 363 days a year," Stansbury says. Intuit's peak demand is generated by its flagship TurboTax product the last two days before taxes are due, April 15. Intuit gets softer peaks from go-getters who file taxes as soon as W-2s come out, and from people who miss the April 15 deadline and file late. For QuickBooks, Intuit sees soft demand peaks from people reassessing their personal finances after the expensive winter holidays, as well as during payroll signup at the beginning of the year.

Why Amazon? When Intuit was searching for a cloud provider three years ago, Microsoft Corp. (Nasdaq: MSFT) Azure was still a "Windows show," while Intuit mostly runs Linux, Stansbury says. More recently, Microsoft has embraced Linux in Azure, and if Intuit were making the choice today Microsoft would be more attractive.

And Google (Nasdaq: GOOG) three years ago was focused on compute, storage, network speed and other basics, but lacked the "richness of services that Amazon had, that you could take advantage of to build your application," Stansbury says. "At that point they didn't have the enterprise maturity. That's shifting. They have more services. And enterprise maturity is growing."

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Which leads to the question of why Intuit went to just one cloud provider. Why not hedge its bets -- as many companies do -- and patronize two or more vendors, to play them off against each other and avoid vendor-lock in?

Vendor lock-in is an engineering issue, Stansbury explains. "Engineers love compatibility layers. They've got this fear of being stuck with a particular vendor who might hose them later." But Stansbury says he's more concerned that by choosing a multivendor approach, Intuit might lose out on extensions available only on a single cloud platform. "I worry more about how you limit all your engineers to the least common denominator capabilities of the vendors you might ride on top of. And the work it takes now, in real-time, with real-time today dollars, to keep abreast," he says.

"In the case of virtualization, the cost of porting from Provider A to Provider B is less than the cost of building a compatibility layer and hampering your engineers," Stansbury says.

— Mitch Wagner, , Editor, Light Reading Enterprise Cloud.