They way at least FB is using a monorepo is very different than any kind of monorepo most people imagine. It's not just about tooling, git itself could never handle it. I am all about using a monorepo but Google and FB having one is not the an argument for it.
why would you tell anyone that they barely passed an interview and why pay an intern according to interview performance? I think the issue here is not the interns
That's actually part of the definition of a calorie: "The modern (small) calorie is defined as the amount of energy needed to increase the temperature of 1 gram of water by 1 °C"