I was approached by some Google recruiter for a very specific engineering management role based on my background. I also thought the same about that general pool thing before that.

The process seemed quite different from what I've read here about the Google software engineer recruitment process.

(After a few phone calls/interviews I realized this was not a position I would likely enjoy, all things considered, so I told them I thought I was bad fit because of A and B, but please keep me in mind if you have another opening that's more suitable.)