how do you demonstrate this?
how do you demonstrate this?
The code that they select tells a lot and is a great starter for further discussion and finding out about how they think. It also demonstrates an essential skill, and that is evaluating other peoples work and how to work with it rather than against it.
Someone who can show their own past work, either open-source, side-project, launched projects, or work at somebody else's company ... well there is a high chance that they can at least code their way out of a wet paper bag. Probably more than that too.
Another, perhaps better, approach is to just hire a few of the most promising candidates for a couple of days. Give them a small project. See if there's a fit.
I think that the issue is not only about predicting future success but about trust as well.