Literally nothing in the first paragraph is true. For driver interaction, if it wasn't a push notification in the app then it would have been some sort of driver operations community tool like zendesk or similar.

> It was like 25k people in a single room iirc.

This never happened. I literally could not have happened. Uber ditched Hipchat when it was around 10k employees. The largest rooms I ever saw were outages or eng rooms with a few thousand, most with the room muted unless they needed something.