Leetcode with no prep is a pretty decent coding skill test
The problem is that it is too amenable to prep
You can move your score like 2stddev with practice, which makes the test almost useless in many cases
On good tests, your score doesn't change much with practice, so the system is less vulnerable to Goodharting and people don't waste/spend a bunch of time gaming it
Cynical, but correct. I've long maintained that these trials, much like those we encounter in the school system, are only partially meant to test aptitude. Perhaps more importantly, they measure submissive compliance.
> On good tests, your score doesn't change much with practice, so the system is less vulnerable to Goodharting and people don't waste/spend a bunch of time gaming it
This framing of the problem is deeply troubling to me. A good test is one that evaluates candidates on the tasks that they will do at the workplace and preferably connects those tasks to positive business outcomes.
If a candidate's performance improves with practice, then so what? The only thing we should care about is that the interview performance reflects well on how the candidate will do within the company.
Skill is not a univariate quantity that doesn't change with time. Also it's susceptible to other confounding variables which negatively impact performance. It doesn't matter if you hire the smartest devs. If the social environment and quality of management is poor, then the work performance will be poor as well.
I think LC is used mostly as a metric of how much tolerance you have for BS and unpaid work: If you are willing to put unpaid time to prepare for something with realistically zero relevance with the day-to-day duties of the position, then you are ripe enough to be squeezed out.