The solution is simple: pay candidates for the estimated time the assignment should take, based on the median rate of the role they're applying for. Pay them regardless if they pass or fail the test. You should be able to avoid grifters looking for handouts if your screening process is any good. But I don't think this type of evaluation is a valuable signal anymore in the age of AI. Anyone could nowadays finish your…
I am totally surprised that "reading code" is not really appreciated even at FAANG companies though very likely that is one of the most important things they will end up doing.