If you did a good job at the last company you'll probably do a good job here.
If you did a good job yesterday, you'll probably do a good job today.
For the most part they are usually correct.
Even the coding interviews are just a signal against overall performance given a short amount of time. It's only a sample of data, but if you did your interview right you should be able to protect some against bad people getting very lucky. Just like driving a car; bad drivers tend to stay pretty bad, and good drivers tend to stay safe. Even though there's a lot of ways to define what is a good driver, there's clearer ways to define what is a bad driver, and if someone was a bad driver yesterday they are still probably a bad driver.
He would go around to people and say "I heard Joe sucks". If the people strongly defended Joe, he was probably pretty good. If nobody stuck up for him, Joe might indeed suck.
I'm only half-joking here. To me, YT algorithm seems to be a mix of "show random videos you've already watched" + "show random videos from channels and users you watched" + "show the most popular videos in last few hours/days/weeks". It's pretty much worthless, but what are we expecting? Like all things ad economy, the primary metric here isn't whether you like the recommended content, or whether that content challenges you to grow - it's maximizing the amount of videos you watch, because videos are the vehicles for delivering ads to you.
Years ago, there is an app stumble upon. I always find it engaging. Hard to get bored.
Hundreds of times I have told youtube im not interested in a recommended video that i have already watched, seems to be completely ignored.
I often watch the same video that I've already watched, many times music, many times comedy, many times something I want to link to another person but end up watching some/all again as I find it, often if I remember it being interesting (e.g. a VSauce video or a Dan Gilbert TED talk), sometimes if it was a guide or howto that I want to follow - e.g. a cooking instruction.