alt Hacker Newsleetcodes as much as we dont like them. could help to reduce bias. you either pass or fail them at the very least. now too much is being left to hand waving, interpretations can be charitable on the mood of the interviewer, or the opposite.
One could even think of: https://en.wikipedia.org/wiki/Hungry_judge_effect
Although I do appreciate, giving green minds the chance, I cannot help but think hiring managers will read into "A Little Bit of Slope Makes Up For a Lot of Y-Intercept" as an excuse for ageism. Which the industry is already pretty rife with.
The issue that most people bring up is that it optimises for people with free time who can work on these things out of hours.
The same arguments are made against take-home tests.
Personally I'm not sure we can do anything really except try to make ourselves excellent judges of character when interviewing... because people will optimise for the interview if they know what's coming.