The number of degrees of freedom between any two people is remarkably small. As someone who has interviewed and hired perhaps two or three hundred people over my career, it was rare that as an interviewer I didn't know more about the interviewer than their resume stated. Later in my career, the depth of information in "ATS" (Applicant Tracking Systems) applications at companies has only gotten deeper. Social media posts, comments on HN :-), peer analysis from others hired from the same company, Etc.
What is more, from Google's perspective, a lot of their hiring teams who used these systems to screen candidates were contractors and have often been laid off when Google needed to make better numbers. They didn't just "forget" everything they knew, a number of them with whom I worked, contacted me post Google employment after setting up their own business as recruiters.
Not saying its good or bad, just that it is important that a lot of information exists that "follows you" around. The longer you work, the more senior you become, the more it fills with a ratio of "haters/meh/supporters" info.
The thing that always annoyed me and I had to ASK recruiters to send me candidates that matched but their "whisper network" suggested they were problems/losers. Sometimes just getting past that screen is really tough for someone.
EDIT: sometimes the wording is tricky.
"Recruiter will supply all sources of information consulted prior to offering candidate for consideration, if it is discovered that undisclosed sources were used, recruiter agrees to forfeit their fee."
Employed on site recruiters you can have a good conversation with and say "Even if you hear they are not good, if they check the boxes on where we're looking I would like to review." Which, given they are evaluated by candidates delivered rather than candidates hired, works out.
Interviewers don't know whether your projects were successful or not (and often don't care, I don't remember ever being asked this type of questions, SWE interviewing has always been mainly technical for me).