Google is changing the promotion process such that managers have much more power (for all promotions up to level 5 == senior swe).
Previously it used to be, as Michael says, very much in the hands of the committee members who never heard about you or even your team.
Now the committee will be composed of your manager and some other two managers from a related team. The committee will not see your own promotion rationale or your own description of your projects and achievements, rather it will be the job of your manager to present these points and advocate on your behalf. The committee (except for your manager) will also see only limited peer feedback compared to before -- no free form text, only multiple choice questions/answers.
If all three managers agree that you meet the bar, you get promoted.
Sounds like googlers should go manager shopping then. If your manager is too passive or doesn't care for what you're working on, you'll be in the same boat.
I would trust my manager to not abuse that power. If he would start using it, I'd first try to change team or, if not possible, just change employer. Hopefully, for the sake of the organisation, people quitting would reflect badly on the manager over time.
The point being, it's much easier for me to manage the relationship with my manager than with some anonymous committee that doesn't even know me. The manager is already important enough that I would not keep him if he seemed more interested in personal agendas than his subordinates.
Previously it used to be, as Michael says, very much in the hands of the committee members who never heard about you or even your team.
Now the committee will be composed of your manager and some other two managers from a related team. The committee will not see your own promotion rationale or your own description of your projects and achievements, rather it will be the job of your manager to present these points and advocate on your behalf. The committee (except for your manager) will also see only limited peer feedback compared to before -- no free form text, only multiple choice questions/answers.
If all three managers agree that you meet the bar, you get promoted.