[cosmodisk]

I do the same. The last hiring I did, I sent them a homework assignment that shouldn't take more than an hour. Then, we started talking about it. I asked to explain what and why was done. The started expanding into the sides areas of the solution. Then zoomed out and we discussed what would be the implications of doing x,y,z in a wider context of the system. The natural flow of the conversation does a couple of things: their social skills and how they approach unknown situations. I've hear plenty of 'I don't know' which was absolutely fine and much better than some fake confidence.