[johnny99]

Middle-aged dad here (not a recent grad). I agree that asking 3-4 days of a candidate is too much. But if the ask is more reasonable (one or two days, perhaps spread out), the candidate is paid market rates or higher, and the project is well-defined, I think this can benefit both parties. The last point is important: doing this requires work on the part of the company, and the participation of a member of the engineering team for both guidance and evaluation.

I did this myself before starting my current gig and was glad I did--I started the job confident that I liked the work, and the people. And by paying market rates you essentially get a small signing bonus. Consulting rates should be higher than the equivalent salaried hourly.