“The operating system is no longer the most important layer for us,” was the message from Microsoft CEO Satya Nadella yesterday.

Microsoft had a big day for Surface, introducing new hardware for the holiday season and teasing dual-screen devices like the Surface Duo and Surface Neo that are coming next year. But it was Nadella’s interview with Wired that really stood out. “What is most important for us is the app model and the experience,” revealed Nadella, further cementing that Windows has slipped down the importance list at Microsoft. “How people are going to write apps for Duo and Neo will have a lot more to do with each other than just writing a Windows app or an Android app, because it’s going to be about the Microsoft Graph.”

He’s right, of course, and it’s something that Microsoft has been signaling since Nadella took over as CEO more than five years ago. Nadella reshuffled Microsoft’s Windows division last year, leading to the departure of former Windows chief Terry Myerson and the core development of Windows being moved to a cloud and AI team. I wrote “Microsoft is ready for a world beyond Windows,” last year, and many of the points are even more relevant today.

Windows is still a significant part of Microsoft’s business, but it’s not the future of it. Nadella is signaling that by focusing on the Microsoft Graph, a collection of APIs that connects devices to Microsoft’s cloud services and acts as an important gateway into Windows, Office 365, and Azure. It looks like Microsoft is partnering with Google to connect this Graph deeper into Android.

Microsoft was vague on the details of its partnership with Google during its Surface event, but the company did announce a new Surface Duo phone running Android. It’s a significant shift, and a return to smartphones for Microsoft, just without Windows this time. Microsoft is now an Android phone maker, and the company’s chief product officer, Panos Panay, was happy to reveal why during an episode of The Vergecast this week. “Because there [are] hundreds of thousands of apps, and you want them,” explained Panay. “It’s pretty simple. Like, literally, you need the apps.”

Another smartphone running Windows would have flopped without these key apps, and Microsoft has now turned to Google to get access to the Play Store and perhaps a little more. Microsoft has hinted that it’s working directly with Google on dual-screen devices for Android, and some additional API work to improve the experience.

That could mean Microsoft is adopting Android in a way that it will contribute back to the Android Open Source Project (AOSP), similar to how the company has adopted and is improving Chromium. If that’s the case, then it really looks like Microsoft’s future is built on Google’s code, but Panay doesn’t seem to think Windows isn’t important anymore.

“No, no, no, no, no, no, no, no,” says Panay in response to the possibility of Android being the future for Microsoft. “You want to give customers what they want in the form factor that they’re using. We’ve learned this — let’s put the right operating system on the wrong product or the other way around. But what’s the right operating system for the form factor? And in this case, on mobile devices, Android’s the obvious choice. But anything [bigger than] that, Windows is everything.”

Windows is still important for people using it right now, but Nadella knows it won’t be soon. Corporate customers still rely on Windows for legacy desktop apps, Microsoft Office, and much more, but elsewhere the majority of computing has shifted to mobile. Apps are increasingly becoming more cross-platform, and relying on web technologies instead of native operating system hooks. Microsoft followed this trend with its many Android and iOS apps, and by bringing Office to the iPad nearly five years ago.

Microsoft is now focused on ensuring things like Office and Microsoft Teams shine on every operating system. That does mean that developing and improving Windows is less important for the company, but improving Android and Chromium so that Microsoft’s apps and services can run better is an obvious move. Panay calls this “creating APIs that create magical experiences across dual screens,” and if Microsoft is successful, then it could mean we’ll see far greater integration between Windows and Android than exists today.

How Microsoft achieves that with Google remains to be seen, but Nadella is describing it as “an app model that spans experiences across devices.” Microsoft revealed the bare minimum of details at its Surface event, promising more software information in the coming months and at the company’s Build developer conference. If Google is willing to open up Android to more Windows integration, then you can guarantee it will want more access to Windows as part of the deal.

Microsoft has already embraced Android as the mobile equivalent of Windows, so if this partnership is done correctly then maybe we’ll see better Google apps on Windows, or Microsoft allowing Windows 10 users to search Google from Windows search. Microsoft has tried to force its defaults in Windows for many years, and Google went out of its way to thwart Windows Phone and Microsoft’s Edge browser work. It’s about time both Google and Microsoft offered the best solution for its mutual customers.

Nadella’s not-so-subtle hints about the future of Windows won’t mean much right now, but it’s clear Microsoft will increasingly partner and make sure its apps, services, and even hardware work best no matter what operating system runs underneath. Windows is by no means dead, but it’s gradually slipping down Microsoft’s list of priorities.