That is not true at either Meta or Google. Final hiring decisions are made by either hiring managers directly or by a committee of senior engineers/managers if

That is not true at either Meta or Google. Final hiring decisions are made by either hiring managers directly or by a committee of senior engineers/managers if the interviewee is not placing directly into a team. HR is there to make sure you’re not making biased decisions against protected classes or to flag if the candidate said something inappropriate in an interview or something, but they have no say in evaluating the candidate’s ability to actually perform the job. That evaluation is based almost entirely on the interview feedback; once a candidate is in the interview loop, grades make very little difference.