I was old (55, at the time), and that seemed to actually upset the interviewers.
I had all the right buzzwords, but as soon as they saw my grey coiffure, the process started going sideways. Somehow, they seemed to think that a 30-year-old could have 30 years of experience.
I was treated pretty shabbily, a couple of times. It was clear that I was considered a waste of time.
I only made it to a test a few times. I failed the BTree part of one test (of course), and they didn't seem to like what I returned in a take-home, once. I also once failed a Swift test (I had just started programming in Swift), when I applied for an ObjC job. Otherwise, I did passably (but probably not outstanding) on the tests.