Even a skills-based test like welding, you do run up against a limited number of real standards, unlike coding interviews. What materials are you joining, measurements, what process are you using, do we have particular requirements about penetration, non-destructive test results, tensile strength, etc etc. That's the problem with modern development not having a central certification or licensure or a standards board/bar, everyone tests something different even if they think they're testing the same thing and it's a depressing mess.

> The general issue with coding interviews is most companies don't validate that the interview is actually correlated with job performance. Of course a process where the blind leads the blind is going to have issues.

Yes, I was looking for someone to finally say this!

Without the feedback, the process is much more like an initiation ceremony to "legitimise" the hiring of the new employee. You put them through an fairly arbitrary ordeal so they can finally be crowned as a proper employee.