There was one company I applied to, for which I passed the screening and the technical interview, that I got a "Welcome Aboard" email from which also included paperwork for getting started. I just needed to meet the CEO as a last step, but they told me it was basically a formality and that I was hired.
I arrived on time and was told to wait outside the CEO's office. Through the wall, I could hear him talking to someone over the phone about football and what flavor chicken wings he wanted to have ordered and delivered to him. I sat there for 25 minutes hearing his muffled dudebro voice ramble on as if his schedule was clear for the day.
Finally, he let me in. At least he remembered my name. I told him why I wanted to work for Acme Corporation and the skills I planned on bringing to the table. He told me almost nothing and had me out of there in less than 10 minutes.
Not even an hour after I left did I receive an email from the same HR person who told me "Welcome Aboard!" that they wouldn't be moving me forward in the hiring process. It was one of the most devastating moments in my life because that initial email and the phone call I got after was a sign that my shitty life was finally going to turn around.
It did help teach me a good lesson that I would learn multiple times(with much softer landings) later on, which is that most people involved in hiring don't know what the hell they're doing and that just because a company makes a lot of money doesn't mean that forms of insanity aren't baked into their processes. You've just got to let rejections roll off you.