Aerial photo of the Windows team taken on the soccer field at Microsoft
Quote in part.... Windows is a beast.
Thousands of developers, testers, program managers, security experts, UI designers, architects, you name it.
And that’s before the supporting cast of HR people, recruiters, marketing folks, salespeople, lawyers, and of course many managers, directors, and vice presidents for each of the disciplines mentioned above.
The entire ensemble cast is supported by many thousands of others at partner teams (within Microsoft as well as outside) that deliver everything from hardware underneath to device drivers and applications on top of the platform.