Rejection doesn’t mean difficulty. All of my worst students work for one of those companies. All of my best were rejected by the same company. Trust me; the competence gap was astronomical.
I agree with this, and I had students like that too, but no way, not in the case of this particular company. It had to be deliberate, or maybe they were just hiring their drinking buddies. I don't know, but it could not have been anything approximating engineering competence.