What a paid trial task is actually testing

Version one was a weekend project. It selected for people with free weekends, which correlates with almost nothing we care about and against several things we do — caring responsibilities, an existing demanding job, a life.

Version two was a two-hour live coding session. It selected for people who perform well while watched, which is a real skill and not one this job needs.

Where we landed

Four hours, paid at the candidate's own day rate, on a real problem from a real project, done whenever suits them. They keep the code and we do not use it.

An unpaid take-home is a transfer of value from the person with less power to the one with more. That was enough of a reason on its own; it turning out to be a better signal was a bonus.