On that day, in Barcelona, Sinofsky will preside over the public test release of the Windows 8 operating system, the most important new version of Microsofts cornerstone product in a decade. Optimised for touch computing and low-power microprocessors, Windows 8 will run on tablets as well as desktops and laptops and maybe even on phones in the future. If it takes off, it could extend one of the most lucrative franchises in business history and restore some cachet to the fading Microsoft brand. It could also propel Sinofsky to the top job at the company when CEO Steve Ballmer eventually steps down.
Frank Artale, managing director at Seattle-based venture capital firm Ignition, which was founded by a group of former Microsoft executives, said Sinofsky has both the tech chops and the panache and showmanship needed for the job.
Supporters credit Sinofsky with bringing order to the sometimes-chaotic software development process at Microsoft partly by cutting layers of management through what is now referred to internally as Sinofskyisation and getting products out the door.
Critics say he lacks the necessary charisma for the top job, and question whether he has the technical brilliance of Gates or the incisive analytical ability and forceful personality of Ballmer .
Most agree, though, that a strong performance for Windows 8 would all but make him the heir apparent.
Microsoft declined to make Sinofsky available for interview.
The Mobile World Congress in Barcelona will be the biggest stage yet for Sinofsky, 46, who is largely unknown outside of tech circles.
Born in New York but raised in Florida, where his father ran a sports goods store, Sinofsky joined Microsoft as a software design engineer straight out of graduate school in 1989. He quickly caught the eye of then-chief executive Gates, who took him on as his technical assistant.
It was in that role that Sinofsky, while visiting his alma mater Cornell in early 1994, wrote to Gates to recount how the students and teachers had already come to see email and the Internet as ubiquitous and expected as regular phone service.
Gates credits Sinofsky, and his contemporary J Allard the force behind the Xbox for helping him to see the full extent of the Internet revolution. Following his stint in Gates office, Sinofsky was assigned to the Office team, which rivals Windows as the companys most profitable product. He was elevated to vice president in 1998, and after successfully driving the development of Office 2003 and Office 2007, he established a reputation as a shipper, a high honor at the company which values getting finished products into the market more than anything else. He was moved over to the Windows unit in 2006, taking charge of it in 2009.
Despite his powerful position, Windows colleagues say Sinofsky known by his internal e-mail handle as SteveSi still takes the time to reply to emails personally and is usually chatty in the hallways, though he may not always be the figure that people want to see coming the other way.
Meetings with Sinofsky can be tough, colleagues say, but he doesnt swear like Gates or scream like Ballmer. Sinofsky has blogged at length about his management ideas, and even taught a management class at Harvard Business School. Some of his best blogs were used as the basis for a book called One Strategy: Organisation, Planning, and Decision Making, published by Wiley in 2010, which he co-authored with a Harvard academic.
Sinofsky stresses balancing what he calls bottom-up ideas from coders on the frontline with the top-down needs of managers who have to make sure the product matches the strategy.
Its a bottom-up plan that is built and locked in a systematic way, said a former senior executive, who worked with Sinofsky in the Windows unit. Everyone gets input on the plan, but once the plan is set, its set.
Sinofsky is no longer involved in the day-to-day minutiae of coding: My code was always nice and orderly, but I probably couldnt write enough code fast enough to really be the very best at programming, he wrote in 2005. But he has the knowledge needed to crack the whip on those who are.
Sinofsky joined the Windows unit at the tail end of 2006, just after the ill-fated Vista was released to PC manufacturers and being prepared for its full public launch in January 2007. His first job was to develop a more ordered process for the next release. That work came to fruition three years later with Windows 7, which has now sold 525 million copies.
Sinofsky writes in his blog about cutting the number of managers between him and the lowest rung of the Windows unit to three or four from seven previously. This streamlining, along with rigorous planning, has become his signature at Microsoft, but has ruffled some feathers at the company because it has reduced the number of general manager positions, where people got to use a wide variety of skills, and focused instead on the core functions of making software: developing, testing and managing specific programs. But few dispute the results. For sure it flattens the organisation, it definitely eliminates fiefdoms, said the former Windows executive.
Physically and temperamentally, Sinofsky is almost the opposite of CEO Ballmer.