I worked in Microsoft half a year, in Redmond.
Very toxic place, often left hand does not know what the right does.
A lot of meetings, a lot of ambitions, a lot of timewaste.
And 50% of all engineers are testers. Miserable work.

And no, it is not like you said, "1000 people".Actualy all 50 buildings are completely full, three people in a room.