[nsb1]

100% this. I've interviewed a great many candidates over the years, and the coding exercise has always been an incredibly valuable litmus test. It gives the interviewer a chance to see whether or not the potential employee has the knowledge of the language and skills needed to do the job. If a developer can't even figure out how to do a basic function on demand, how are they going to be able to contribute to the team? If a developer won't do a basic function on demand, then that's an instant disqualification. Anyone can say anything on a resume, and there needs to be a way to validate that it's not just a fabrication.

To be clear, I am making the distinction between "coding exercise" and "brain-teaser". Brain-teasers are not useful in an interview context, and only result in adding stress to an already stressful situation. Simple tasks like "Write a function that rolls two dice and calculates the position of a game piece as it moves around the edge of a game board" are much better. I am not looking for the candidate to give me their masters thesis in a piece of code on demand, I am looking to weed out candidates that clearly don't have the skills to fill the position.