>Harder questions ultimately filter out too many qualified candidates to be optimal. This was the key sentence if anyone missed it. "Optimal" for whom, exactly

>Harder questions ultimately filter out too many qualified candidates to be optimal. This was the key sentence if anyone missed it. "Optimal" for whom, exactly? Not for FAANG certainly. They don't need to worry about filtering too many candidates out, because they have a nearly infinite pool of applicants, and infinite money to conduct a search. They can ask as difficult questions as they want, because they can pass hundreds and thousands of qualified candidates, and still have plenty more where that came from. Edit: If you consider "optimal" to be the expected cost of a hire compared to the expected profit, it is fully plausible that if your margins are big enough, asking hard questions is the most effective way to ensure low false-positives. But as everyone knows, comments on articles about interviews are never about the economics, it's only about human ego of feeling rejected.