If you give candidates a take-home technical exercise, accept and expect that they will use AI to solve the problem. Shoot, encourage them to do so, because that is what they’ll be doing on the job anyway, right? Measure not the method used to arrive at the result, but the ability to recognize good, clean code. You can—and should —ask the candidate to explain their code if you are concerned about it.
I’m not a big fan of whiteboard coding exercises. Many people don’t perform well under direct pressure, and “thinking on your feet” is not a skill you should be interviewing for. In the real world, developers have the time they need to ponder over a problem. You don’t want them writing code off the cuff, so why would you use that as a measure for hiring someone?
If you build it
One final thought: First impressions are important. I can generally tell if someone will be a hard no in the first five minutes. Usually it takes a complete interview cycle to get to a yes. That said, there have been times when I knew was going to make an offer after five minutes. Don’t discount that initial assessment.