Product manager R&R in Facebook Google Microsoft

Can fellow PMs share your roles and responsibility as a product manager in these firms? I heard in google, engineers make product decision, not sure what exactly is PMs responsibility. In Facebook, PM owns metrics and strategic direction, engineers can make small feature level product decision, PMM help on some admin stuff like documentation for PM. In Microsoft, program manager focus more on project delivery so it’s more on technical side. Is this too general? Care to share your experience? I am talking to all the them so would love to learn more about the difference in each firm.