Urs Hölzle oversaw the creation of the world's largest computer. It's a machine that spans the globe—from The Dalles, Oregon to Hamina, Finland to Quilicura, Chile—and you use it every day. It's called Google.

In 1999, when Hölzle was a computer scientist at UC Santa Barbara, Larry Page and Sergey Brin asked him to help rethink the hardware and software underpinning the Google search engine. At the time, Google Search ran on about 100 computer servers in a single Northern California data center. Over the next 15 years, alongside some of the brightest minds in computer science, Hölzle transformed this tiny collection of machines into a global network of data centers that operate very much like a single system, allowing Google to operate a vast empire of web services, from Search to Gmail to Maps to Apps.

>He's the man most responsible for ensuring that Google's services run as efficiently as they do.

With an air of extreme confidence—not to mention a diamond stud earring—the Swiss native heads Google's technical infrastructure team, known as "TI" inside the company. When he discusses other Google teams, Hölzle calls them his "customers." Hölzle and his TI engineers provide the infrastructure that these teams use in delivering web and mobile services to millions upon millions of people. He is, in short, the man most responsible for ensuring that these Google services run as efficiently as they do.

But this past January, Hölzle sent a thunderclap of a memo across the company. In it, he laid out a new direction for both his team and the entire empire. In the months to come, he wrote, he and his team would give a little less attention to internal "customers" so that they could concentrate on serving a new kind of customer outside the company. They were preparing a major expansion of the company's cloud computing services—services that let outside businesses or software developers run their own software atop Google's infrastructure. "We will spend the majority of our development efforts on this New World," wrote Hölzle. "Every developer will want to live in this world...and it's our job to build it."

Google has long offered cloud services. It unveiled a service called Google App Engine in 2008, and in 2012, it followed with a sister service, Google Compute Engine. But in this market, the company has always trailed Jeff Bezos and Amazon, who pioneered the idea. And for years, Hölzle and company treated cloud computing as a sideline. Now, he says Google is intent on turning this into an enormous business, a business whose revenues could even surpass what the company pulls in from online advertising.

That may seem like a stretch. Online advertising has made Google one of the richest companies on earth. But Hölzle's point is that the potential market for cloud computing is even bigger. "It has become clear that the public cloud is the way of the future," Hölzle says. "One day, this could be bigger than ads. Certainly, in terms of market potential, it is."

To be sure, Hölzle is looking years down the road. But he isn't the only technologists who believes that cloud computing will slowly eat away at the $600-billion information-tech market. According to James Staten, an analyst with tech research outfit Forrester, cloud computing will account for about 15 percent of this IT market by 2020—that's $40 billion—and much like Google, Amazon believes cloud services could become its biggest business.

>'It has become clear that the public cloud is the way of the future. One day, this could be bigger than ads. Certainly, in terms of market potential, it is'

At the moment, Amazon still dominates cloud computing. The company invented the market with services like the Elastic Compute Cloud, a way of instantly running software, and the Simple Storage Service, a means of storing large amounts of data. And other rivals abound, including Microsoft's Windows Azure service and Rackspace's Cloud. But Hölzle believes that Google's vast infrastructure gives the company an edge. "We've done much of the hard lifting already for our internal needs," his memo read. "We have a latent advantage in this business."

In fact, Google operates a much larger online infrastructure than Amazon or Microsoft. Google's global network is larger than all but one of the companies that provide the backbone for the entire Internet—and it's widely acknowledged that this massive computing system is the world's most technically advanced. Over the last 15 years, Hölzle and engineers like Jeff Dean, Sanjay Ghemawat, Luiz Barroso designed entirely new kinds of data center hardware and software in order to keep up with this growth.

The question is whether Google can translate this into a different kind of success. The best technology doesn't always win the day. Marketing can play a role, but so can timing, or luck. "Google has the best infrastructure. They have the best engineers. They have the best software. I firmly believe that," says Mike Miller, a founder of a cloud computing company called Cloudant, which is now owned by Google rival IBM. "But the trick is that's not always enough. Think back to Betamax versus VHS."

'The World's Biggest Cloud' —————————

Google's new push begins tomorrow morning. At an event in San Francisco, the company will unveil several changes to its portfolio of cloud services, while providing a look "behind the scenes of the world's biggest cloud." In a rare public appearance, Hölzle will give the keynote, laying out his vision for the future of the market.

Like other cloud giants, Google and Hölzle aim to make life easier for anyone who's building a new website or a new mobile app, storing or processing large amounts of data, or just trying to see if some code will run. Businesses and developers can just open up a web browser and run their software on Google's network. According to Google, its cloud services already run 4.75 million active applications, including names like SnapChat and Pulse. Google App Engine alone handles 28 billion online requests a day, or about 10 times more than Wikipedia. But the process should be far easier than it is today, Hölzle says.

>'What you really want is to mix and match,' Hölzle says, indicating the company will combine the advantages of App Engine and Compute Engine.

Today, if you build a website on Google App Engine, the service will automatically expand the site across more and more machines as more and more people visit it. The problem is that you can't just hoist any software onto the service. You have to build your site in a certain way, using specific languages, software libraries, and frameworks. The company's other service, Google Cloud Engine, addresses that issue, giving you raw virtual machines where you can run anything you like. But the onus is on you to manage these VMs—to spin up more, for instance, as you need them. Hölzle tells me that Google has now bridged the gap. "What you really want is to mix and match," he says.

Hölzle also says that cloud computing is too expensive. Indeed, many small businesses and developers complain that cloud services can be far more expensive than buying and operating your own gear. It would seem that companies like Amazon charge a high premium for their services—at least in certain cases. But Hölzle believes that because Google is operating at such an enormous scale, it can help solve this problem. "For cloud success, you not only have to be technically good," he says, hinting that company will also significantly drop prices at tomorrow's event. "You have to economically beat the alternative."

Forrester analyst Staten believes that Google remains a long way from taking control of the market. "Google is still playing catchup," he says. Google's services don't offer quite as many tools as Amazon and Microsoft. That said, he does think Hölzle and company will contend with the Amazons and the Microsofts and the IBMs in the long term, as they all fight for a slice of that $600-billion pie.

The Snowden Problem ——————-

The added rub is that these rivals are fighting more than just each other. Many of the world's businesses are still reluctant to run their applications or store their data in the cloud, fearing it will compromise their privacy and their security. This is a particular worry now that ex-government contractor Edward Snowden has exposed the NSA's efforts to eavesdrop on Google and other big-name web companies. What's more, in many parts of the world, government regulations prohibit businesses from storing data outside local borders. But in typical Google fashion, Hölzle believes that the world will evolve to the point where people realize their data is actually be safer on Google.

Hölzle believes that the world will evolve to the point where people realize their data is actually safer on Google and where government regulations bend for global cloud services.He acknowledges that regulatory issues are largely outside of Google's control, but he says security is another matter. "Cloud based systems are often a step ahead because they evolve more rapidly," he says. "If you look at the long history of NSA disclosures, you actually see in these documents that we are harder to crack than most companies."

Others take a slightly different view of how this market will evolve. Lucas Carlson, a cloud computing veteran who now oversees services at internet service provider CenturyLink, believes there will always be businesses who insists on running their software in-house for security, regulatory, and other reasons. "I think there will always, forevermore, be a balance between the public and the private," he says. But he also believes that public cloud services like Google Compute Engine and his own CenturyLink Cloud will continue to expand their reach, and according to Forrester's Staten, this is already happening. Despite security and regulatory concerns, cloud services are doubling their share of the IT market each year.

As this market grows, the bigger question is what role Google will play. Hölzle makes some bold statements about how far these ambitions can take the company. But Google is already many things—a search company, an ad company, a map company, a phone company, a company that dabbles in everything from computerized eyewear to self-driving cars. More than anything else, it's a company that has mastered the art of global computing. The cloud could become its biggest business.