It sounds like it was specifically for a real, non-trivial problem out of their backlog. > the strongest candidates self-selected into this paid screening chal

It sounds like it was specifically for a real, non-trivial problem out of their backlog. > the strongest candidates self-selected into this paid screening challenge ... > to make developer interviews more valid & inclusive, introduce payments. This still makes them exclusive. Someone with a full-time job who's busy with life could easily not care about $600--they're time-limited, not money limited. They also provide little evidence supporting their motivation of hiring better engineers. I buy that better engineers are better for the company, they just didn't show that paid interviews select better engineers. All that said, I agree that a long-ish, real-world problem is a great indicator of job performance. Paying people just means you're not taking advantage of them. The bigger problem is still around time.