> The fact that there are whole industries built on training these puzzles is a big signal that you're wrong. I'm not sure that logic alone is a compelling: I

> The fact that there are whole industries built on training these puzzles is a big signal that you're wrong. I'm not sure that logic alone is a compelling: It's conceivable that this secondary industry addresses a real gap in university curricula, or a need for ongoing training of experienced developers. But I think your overall point still holds, because there's a consensus that a large number of Leetcode-like puzzles require familiarity with problems and solutions that hardly every come up in real professional software development, and aren't even good proxies for the abilities that do matter.