This was one of the cool parts of Android: Out of the first hundred people, almost everybody had done this before. I was working on things that I had already made mistakes on and learned from. Everybody was.
Android, like basically every other piece of technology, is not so much the product and releases that ship as it is the people who built it and the collective experience that they brought to bear in shaping it. So the story of how Android (the phone OS) came to be starts much earlier than the startup, in the collective histories of the people on the team.
Android happened because so many other efforts happened ...