I am looking for examples of ex-Googlers or Ex-Microsofters ( or other big companies leavers) who, after leaving the established company, went on to build their own, became hugely successful in their own companies, and then managed to sell back their startup to their former employers or having a mutual beneficial relationship with their former employers, in the way that wouldn't be possible if they didn't leave and strike out on their own in the first place.
I am sure I've read some, but couldn't remember the specific examples. Anyone has any idea?