To my mind the ideal challenge is no more than 4 hours. You make an appointment. At the agreed time, the hiring company emails you the requirements. If you have

To my mind the ideal challenge is no more than 4 hours. You make an appointment. At the agreed time, the hiring company emails you the requirements. If you have clarification question, they remain available throughout the challenge time to answer them. From a hiring point of view the challenge should have some vague areas in the requirements in order to test whether the candidate is a coder or a developer who asks decent clarification questions. The challenge requires no special tools to do, either JS in a browser or Python or something like that. The exact requirments of the dev environment are specified at the time the appointment is made, i.e. if you want the person to develop in Python 2.6.3 or to use JS with backbone.js, then the candidate can get set up in a few minutes and be ready. I consider 4 hours to be a max. 45 minutes is a bit short IMHO and does not allow for including unit tests. Also, I believe that a good challenge should ask for a complete set of unit tests as well. But a full working MVP is way overboard and is too complex for the hirer to make meaningful decisions based on the outcome. Any challenge should be followed up by an interview in which questions focus on the solution as developed by the candidate. The why of choices and the intent are important factors, probably more important than the actual code.