As a non-CS graduate looking for my first full-time job as a Junior Developer I can only ask one thing of prospective employers. Please give clear feedback that will help give direction to the candidate if you reject them. I have done a number of code challenges and while I don't mind doing the challenges (I look at them as training) and I can always create a working solution there is nothing worse than receiving a s…
Only do a code challenge if it takes a <=4 hrs. If it takes longer than that, then make sure it's a substitute for the onsite whiteboard portion. If they're using a code challenge, in addition to the whiteboard interview, and as a first pass filter, walk away.