Steven Sinofsky remains very active after his retirement from Microsoft, now signing on with Box as an adviser for its cloud storage and file sharing service, its developer platform and its mobile applications.
The news comes a week after Sinofsky announced that he had joined Andreessen Horowitz as a board partner, representing the high-profile venture capital firm on the board of companies it invests in.
Although Andreessen Horowitz is one of Box's investors, Sinofsky and Box struck their own deal separate from his work for the VC firm.
There's also a Facebook angle to the hookup. Box CEO Aaron Levie initially contacted Sinofsky about six months ago by sending him an unsolicited message via the social networking site.
"Not only did Steven not block me, he graciously responded. In fact, he even visited Box HQ to learn about what we are working on," Levie wrote in a blog post on Thursday.
Box expects to benefit from Sinofsky's product development experience at Microsoft with products like Windows, SharePoint, SkyDrive and Office, and from his vision for how computing needs to evolve, according to Levie.
In Box's view, the future of enterprise software will be mostly about mobile devices and cloud services, as elements like desktop computers and on-premises server software become less attractive to businesses of all sizes.
"Steven has spent much of his career thinking about technology transformations, navigating them, and — in many cases — helping to drive them," Levie said.
Box's product competes against Microsoft's SkyDrive cloud storage service and in part against Microsoft's SharePoint all-purpose collaboration server.
If Box follows up on indications Levie has given publicly in recent months regarding plans to deepen the product's collaboration capabilities, it will compete even more closely against Microsoft in the future.
However, Box wasn't one of the rivals that Microsoft listed on the retirement agreement it struck with Sinofsky, which bars him from accepting direct or indirect employment with Amazon, Apple, EMC, Facebook, Google, Oracle or VMWare.
Microsoft said it has no comment regarding Sinofsky's contract with Box.
Box has raised more than US$300 million in funding since its founding in 2005 from investors including Draper Fisher Jurvetson. Andreessen Horowitz became a backer in 2011. Levie has said an IPO could happen next year or in 2015.
Box's product is used in 180,000 businesses — including in 97 percent of the Fortune 500 — and by about 20 million people.
The privately held company, based in Los Altos, California, is on pace to more than double its revenue in its current fiscal year, after posting sales growth of more than 150 percent in the previous one, it has said.
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