Earlier in undergrad, I had passed the interviews for an internship at Google. However, I was never matched with a host, so I never received an offer. A recruiter contacted me based on this experience and set up a phone screening, followed by an on-site interview.

At the on-site, I felt that the quality of two out of four of my interviewers wasn't at the standard I expected.

In one interview, I was hurried along and had to repeatedly ask for clarification on the very ambiguous problem presented. It seemed like the interviewer didn't have time for me.

In the other questionable interview, I felt that the interviewer used up a lot of the time just talking, which made me feel pressed for time. Despite this, they had me rigorously explain mundane details, like running a test case to "prove" that heapify has linear efficiency, even when I offered to prove it mathematically in less time.

Everything else was fine, and I'm fairly certain I answered everything optimally. So, I guess you just have to get lucky enough to have all good interviewers that you can click with.