> If someone can learn to solve just DP problems by practicing in leetcode then DP is a useless metric or proxy of someone’s ability to reason mathematically.
Metrics that can be gamed can still have a lot of signal in them because the cost of gaming the metric is higher than the benefit of gaming things.
Also, if being able to learn completely arbitrary things is correlated with intelligence and correlated with job performance, then people who are willing to jump through that arbitrary hoop are telling you that 1) they think they're more capable (faster learners) than average 2) they're willing to put in the effort to prove it to you. Maybe you're not a getting a pure signal of mathematical ability, but some combination of drive + ability + learning fast, and you care about all three.
Dynamic programming is far from completely arbitrary. But even if it were completely arbitrary, it would still serve a useful signaling function as long as people agreed on which hoops they're supposed to jump through.
A peacock's plumage serve little useful purpose except to show how fit he is; but that purpose is essential to the survival of the species.
Metrics that can be gamed can still have a lot of signal in them because the cost of gaming the metric is higher than the benefit of gaming things.
There's a branch of game theory/economics called signalling theory that's applicable here: https://en.wikipedia.org/wiki/Signalling_theory
Also, if being able to learn completely arbitrary things is correlated with intelligence and correlated with job performance, then people who are willing to jump through that arbitrary hoop are telling you that 1) they think they're more capable (faster learners) than average 2) they're willing to put in the effort to prove it to you. Maybe you're not a getting a pure signal of mathematical ability, but some combination of drive + ability + learning fast, and you care about all three.