Before joining Microsoft and becoming one of its most important software engineers, Mark Russinovich was in the business of pissing the company off.

This was the late 1990s, when Microsoft dominated the tech world, its Windows operating systems running so many of the world’s computers, from desktops and laptops to corporate workstations and servers. During the day, Russinovich built software for a tiny New Hampshire software company, but he spent his evenings and weekends looking for bugs, flaws, and secrets buried inside Microsoft’s newest and most important operating system, Windows NT. Sharing his findings with the press or posting them to the web, he frequently pissed off Microsoft, but never so completely as the time he exposed Windows NT as a fraud.

Windows NT represented Microsoft’s future–its core code would underpin the company’s operating systems for years to come–and at the time, it was sold in two flavors. One was for corporate workstations used by engineers, graphic designers, and the like, and the other was for servers. NT Workstation was much cheaper, but, unlike NT Server, it barred you from running web serving software, the software that delivers websites to people across the internet. Microsoft said that NT Workstation just wasn’t suited to the task. But then Russinovich reverse-engineered the two OSes and showed that the truth was something very different. NT Workstation, he revealed, was practically identical to NT Server. It wasn’t that the OS couldn’t run web serving software. Microsoft just didn’t want it to.

The story shows that Microsoft is capable of change–however long that change might take.

The ruse was typical of the software giant, a way of artificially shifting a market in its own favor. It could force all web serving onto a more expensive OS while still selling a cheaper version for other tasks. And after Russinovich exposed the practice, releasing a tool that let anyone transform NT Workstation into NT Server, the company responded in typical fashion. Days later, when employees from his New Hampshire company flew across the country to participate in a Microsoft event, Microsoft barred them from the building. But at the same time, the incident managed to bring Russinovich closer to the software giant. Even as his colleagues were shut out of the company, the head of Windows offered him a job.

Told by the six-foot, five-and-a-half-inch Russinovich in his wonderfully straightforward way, it’s a tale that lays bare the unapologetically ruthless attitude that pervaded Microsoft in the ’90s and on into the aughts, an attitude that brought it enormous success but also landed the company in hot water with regulators and ultimately hampered its ability to compete in the more open and collaborative world of the modern internet. But the postscript to the tale–where Jim Alchin, the head of Windows, tries to hire Russinovich–also shows that Microsoft is more complicated than you might expect, that the company is capable of change, however long that change might take.

When Alchin offered him the job, Russinovich didn’t take it. But after several more years spent running his Sysinternals site–where he published a steady stream of exposés that, in his words, “pissed off” Microsoft and other tech outfits–he did join the software giant. The company made him a Microsoft Technical Fellow–one of the highest honors it can bestow–and today, he’s one of the principal architects of Microsoft Azure, the cloud computing service that’s leading the company’s push into the modern world.

Russinovich is a symbol for a new Microsoft, a Microsoft that’s systematically changing its old ways. Mirroring the company’s technical evolution, he began his career in computer operating systems and has now moved into the cloud. But, more than that, he embodies a new Microsoft attitude. Russinovich has a long history with Microsoft–so he understands the old attitudes and how some of them can still help the company—but, like recently appointed CEO Satya Nadella, he also sees where the company has gone wrong and where it must now travel in order to compete in a world shaped by the Googles, the Facebooks, and the Amazons.

‘I feel that, more and more, Microsoft is embodying the values I’ve always had.’

Today’s Microsoft, he says, is closer to what he wants it to be. “I feel that, more and more, Microsoft is embodying the values I’ve always had,” Russinovich told us last month at Microsoft’s annual Build conference in San Francisco, a conference where the company open sourced its most important software development tools, freely sharing them with the world at large–the sort of thing it never would have done in years past.

Even in small ways, Russinovich belies the Microsoft stereotype. As those inside the company will tell you, he’s unafraid to speak his own mind–something you see not only when he tells the story of his Windows NT exposé, but when he looks back on the NSA spying scandal and its effect on Microsoft. “He’s an independent thinker,” says Rich Neves, who has worked with Russinovich both inside IBM’s research operation and at Microsoft. “He has what you call intellectual honesty.” And as science fiction fans will tell you, he’s more than just a corporate software engineer. He’s the author of three techno-thrillers—Zero Day, Trojan Horse, and Rogue Code–Michael Crichton-esque novels recently optioned by an independent film producer. But he’s also someone who’s actively pushing Microsoft’s into new places, most notably with Azure.

Azure didn’t begin with Russinovich. But, along with Nadella, he’s one of the primary thinkers who pulled the cloud service out of the old Microsoft mindset and turned it into something that can compete for the future. “He has real vision,” says HP cloud chief Bill Hilf, who once worked alongside Russinovich at Microsoft. “And he knows how to listen to customers.”

A Cloud Unleashed

Cloud computing was invented by Amazon. In the mid-aughts, the web giant unleashed services that let anyone rent computing power over the internet, without setting up their own computer servers, and this sparked a revolution in the way companies built and ran their websites and other software applications. Netflix built its TV and movie business atop the Amazon cloud. Dropbox erected its file-sharing operation there.

‘I ranted at some of the architects when I was at Microsoft. They were constraining the sorts of things you could do.’

The Amazon cloud was a threat not only to server makers like HP and Dell, but also to Microsoft, which had traditionally made so much money selling operating system software to these server makers. So, in the wake of Amazon’s success, Microsoft built its own cloud service. Led by people like Dave Cutler, the man who oversaw the creation of Windows NT, the company built Azure.

The trouble was that, unlike the Amazon cloud, which let you build software however you liked, Azure forced you to build it in a particular way, and this was revolved around Microsoft’s own software development tools. For Chris Brown, who helped build the Amazon cloud and later worked at Microsoft, it was a product of the company’s outmoded way of thinking.

“I ranted at some of the architects when I was at Microsoft. They were constraining the sorts of things you could do,” Brown told us in 2012. “Microsoft likes to do a really big up-front design, where they define the physics of a new universe. They birth this new universe, and they say: ‘This is how you do it’–instead of starting out with something simple and letting people show them how it should be done.”

But as Azure struggled to find an audience–and other cloud companies continued to threaten its place in the world–Microsoft slowly let go of this mentality. Under Nadella, the Azure team expanded the system, creating a new service that could run almost anything–including Linux, the massively popular open source operating system that Microsoft once fought so hard to squeeze out of the market. One of the primary architects of this new service was Mark Russinovich.

Cutler Says ‘Thanks’

If you passed him on the street, you wouldn’t peg him as a computer engineer–he looks more like Jon Hamm than Dennis Ritchie–but he has never been anything else. Russinovich completed a computer engineering master’s degree from the Rensselaer Polytechnic Institute in New York and a PhD at Carnegie Mellon, before doing a post-doc at the University of Oregon. He specialized in the design of computer operating systems. Typically, he studied the code at the heart of UNIX, the seminal OS that still underpins Linux and Google’s Android and Apple’s Mac OS, but at Oregon, he moved into Windows.

From the perspective of the tightly-controlled corporate giant that Microsoft had become, Russinovich was still a loose cannon.

Together with another grad student named Bryce Cogswell, he used a federal research grant to explore ways of dealing with crashes and other failures in Microsoft Windows 3.1, the prevailing desktop operating system of the day. After leaving the university, the two moved to separate cities–Cogswell launching a startup in Austin, Texas and Russinovich joining that tiny software company in New Hampshire–but their graduate work soon spawned a sideline business they called Winternals.

Basically, they built new tools for using and hacking Windows NT and other core Microsoft software. Then, as a way of calling attention to these tools–and, in the broader scheme of things, keeping Microsoft honest–Russinovich would reverse-engineer the OS, pinpointing flaws and sharing them with the world through his Sysinternals site and trade pubs like PC Week. In some cases, he even went straight to Microsoft. One of the highlights of his career, he says, was the time he found a bug in the way the OS juggled multiple computing tasks, or threads, and he emailed it to Dave Cutler, the father of NT. Culter responded with one word: “Thanks.”

At the time, Russinovich saw this as a seismic event. He was helping one of his heroes–and this hero was acknowledging his help. But over the years, after Alchin first offered him a job in the wake of the NT exposé, Russinovich became more of a peer to his Microsoft heroes, getting to know people like Cutler and Mark Lucovsky, the man who was so important to Microsoft that Steve Ballmer threw a chair when he left for Google. By the early aughts, Russinovich was helping Microsoft watcher Dave Solomon write a book on the Windows 2000 operating system, and he made regular visits to the company’s headquarters in Redmond, Washington to gather string for the project, growing even closer to the company.1

From the perspective of the tightly-controlled corporate giant that Microsoft had become, Russinovich was still a loose cannon, someone who went after not only Microsoft’s practices but those of countless other tech companies. In 1995, he revealed that a tool called SoftRAM, which promised to expand your computer’s memory, didn’t really do so, and the FTC forced a recall. A decade later, he discovered that Sony was installing what amounted to spyware on people’s PCs, and following another government investigation–and several lawsuits–Sony ended up paying out too.

Nonetheless, in the wake of the Sony scandal, Microsoft offered Russinovich another job. This time he took it, but only after the software giant agreed to buy Sysinternals and keep it going. To negotiate the deal, Russinovich hired Microsoft’s former head of mergers and acquisitions, who had only just left the company. “He knew the playbook,” Russinovich says, “which made things easier.” So, on the side, Russinovich continued to do what he had always done, but now his main task was to hone the code at the heart of Windows, helping to shape new OSes such as Windows Vista and Windows 7. He did this for the next four years, and then, encouraged by Cutler and Microsoft chief technology officer Ray Ozzie, he moved to Azure.

A New Kind of Operating System

An operating system runs on a single machine and a cloud service runs across thousands, but the two behave in much the same way. They allow a collection of interconnected hardware to work as a whole. That’s one reason that Russinovich, someone who worked for so long in the guts of the operating system, is so well suited to building a sweeping cloud service like Azure. “Many of the same architectural principals apply,” he says.

The bigger difference is that Microsoft isn’t in a position to tightly control the way people use a cloud service. The competitive landscape has changed. Many businesses are still reluctant to move into the cloud—for security, regulatory, and other reasons–and if they do move, it’s too easy for them to choose another service: an Amazon or a Google or a Rackspace. But that’s another reason Russinovich is suited to the job.

‘Look at what you’re doing through the eyes of the customer, treat the customer with respect, and assume the customer is smart.’

The company’s decision to refashion Azure as a service where businesses could run practically any software, including Linux, says Russinovich, was a direct response to discussions with longtime Microsoft customers. They wanted a way to move their existing software into the cloud, rather than just building new applications to suit Azure’s very specific architecture. “We needed to give them an on-ramp,” he says, and that’s what he helped design. It’s this kind of simple customer interaction, Russinovich explains, that shows how Microsoft is now aligning with his personal values. “It’s really just following some basics that can get lost in the heat of the drive to grab revenue and maximize profits: look at what you’re doing through the eyes of the customer, treat the customer with respect, and assume the customer is smart,” he says.

Judging from the recent growth in Microsoft’s Azure business, the move has paid off, despite increased competition from Google and Amazon. A Microsoft that runs Linux is a better Microsoft. But for Russinovich, this is merely a first step. The irony is that he believes the world will eventually embrace something that’s a lot more like Azure’s original architecture.

Known as a “platform-as-a-service”–as opposed to an Amazon-like “infrastructure-as-a-service”–the original architecture tightly controlled how software was built, but it also ensured that businesses didn’t have to deal with many of the hassles that typically come with running large software applications, like spreading the software over more machines to accommodate more traffic. The platform-as-a-service handles that for you. This, Russinovich says, should be the ultimate goal.

So he’s now working to merge the platform service and the infrastructure service, giving people the power to run any software while still ensuring this software operates in an automatic way. “We want to blend the two worlds,” he says. Google is moving down a similar road, and, in a way, Amazon is too. Nowadays, Microsoft must compete head-on with rivals, and that’s exactly what it’s doing.

Beware the Zero Day

The added wrinkle is that Microsoft is battling more than just the Googles and the Amazons. Like these rivals, it’s battling widespread concerns that the cloud is less secure than systems that run inside your own data center–concerns that only heightened when ex-government contractor Edward Snowden revealed that the NSA was spying wholesale on the internet’s largest services. But this is another area where Russinovich lends a hand.

He is a novelist who has lived what he writes about.

In running Sysinternals, Russinovich became one of the world’s preeminent security researchers. As he reverse engineered Windows and other software, one of his primary aims was to locate bugs and other vulnerabilities that could expose the system to miscreants–the Sony rootkit being a prime example. It was this work that inspired his first novel, Zero Day, which takes the idea of a cyber attack to its logical extreme, describing a world where Arab terrorists let loose a virus on everything from airplanes and ships to hospitals and nuclear power plants. He was feeding off a lifelong love of techno-thrillers–something that began when he picked up Michael Crichton’s The Andromeda Strain as a kid–but unlike many science fiction writers, he has lived much of what he writes about.

This is why, when the NSA story broke, Russinovich was part of the small team that worked to remake Microsoft’s online security. Much like Google, the company started encrypting all information moving between its data centers and laid down a new set of cryptography schemes. Many still question how effective these schemes will be, accusing the company of secreting collaborating with the NSA and other government organizations to share data through other channels, but Russinovich is quick to say this can’t happen in today’s world. “The risk to the business is monumental,” he says. “Without trust, there is no cloud. You’re asking customers to give you their data to manage, and if they don’t trust you, there’s no way they’re going to give it to you. You can screw up trust really easily. You can screw it up just by showing incompetence. But if you show intentional undermining of trust, your business is done.”

It’s the type of thing Microsoft might have said in the past. But this time, the words ring at least a little differently. They’re coming from Mark Russinovich, and he isn’t what Microsoft used to be.

1Correction 13:40 EST 05/27/14: This story originally indicated that Dave Solomon worked for Microsoft. He was self-employed.