My experience is that if you skip coding challenges, about half of the candidates that otherwise seem fit for the job will not be able to program effectively. Unfortunately most of these will also not be able to learn it within an acceptable time span, even if they feel motivated.
The point of a coding challenge is not to find out if the candidate solves the task in exactly the way the interviewer expects. There are often many different approaches and solutions.
The point is not even to find out if the canditate can solve the task at all.
The point is to give the candidate a chance to show how she approaches a programming task. The solution itself is not important.
While you mentioned some valid points but I can tell you that candidates who ace those programming challenges aren't necessarily a better fit than ones who fare averagely.
Because most people are under duress to perform in an interview so they might blank out there but if evaluated humanely, they're often great problem-solvers and can handle crisis situations equally well. For all one can prepare, even the slightest thing can derail an interview.
Also, I disagree with your statement that coding challenges are solely about approaches and not about solutions since I've had multiple experiences wherein I got feedback my scores were too low inspite of me writing working programs that were logically and syntactically correct.
We want them to be so but often they're taken as the only yardstick to judge people.
I think you misunderstood some of my points because I didn't make them clear enough:
Most coding challenges are done wrong, not the way I described.
Coding challenges should never be the only criterion for selecting an employee.
Stress and anxiety have to be taken into account.
That's very correct but I'm doubtful if companies will shed the approach of NOT counting those code challenges as the only criteria along with accounting for stress & anxiety. The ones that actually care, will have a ready pool of diverse candidates almost all the time.
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