It's not one instance. Most people who have this happen to them don't tweet about it. Every instance could have a "well, you should have ______ better" stapled to it.
I don't think is apple/google. This sounds like the kind of thing small companies do. I would be very surprised if that was FAANG
I am not a fan of leetcode interviews myself, but I don't think the FAANG process is that bad. I am interested in any specific examples of authors of projects being rejected from big-tech companies for a role where they would work on their own thing
Here's another one that I already know exists off the top of my head -- the only thing I have to look up is the tweet url: https://twitter.com/tiangolo/status/1281946592459853830