When he became CEO in 2014, Microsoft was rich but stuck: fighting over Windows, missing mobile, and full of internal rivalry. He talked about moving from "know-it-alls" to "learn-it-alls", which sounds like a poster, but he actually meant it.
He put Office on the iPhone, embraced Linux and open source, bought GitHub, and bet heavily on Azure. Later he made an early, large bet on OpenAI.
None of it was a single genius move. It was mostly letting go of old pride and getting thousands of people to work together again.