There are many reasons why I think this process is broken that others have written so much at length about enough that I'm not going to bother taking the time.
If it's enough for you to say that because you have a test that everyone takes and it filters your candidates so that's proof of ability, without even going into the results and asking if your test is optimizing for the correct things, there's nothing I can say to convince you otherwise.
Anecdotal, but I know about a half dozen people with experience and CS degrees who would blow your filter but can really get shit done and don't really need any training.
Hiring is hard and the real shame of this industry is that collectively we don't approach this problem with the same level of rigor that we do everything else because by and large we consider this sort of work to be beneath us and not worth a significant investment of our time.
I just want to leave my response to your now-deleted followup:
I don't advocate talking to every candidate but I don't think it's possible to estimate someone's skill without talking to them (even email is a form of conversation).
I find much better filters for that sort of thing are ability to follow directions and attention to detail. If you have hundreds of applications, I guarantee they're not all great spellers or communicate effectively. I value the soft skills way above programming ability (since we have to communicate effectively every day) in the early stage.
I find that it's pretty easy to demonstrate that you "have it" from portfolio, resume, cover letter and the application process.
Personally it's a huge pet peeve of mine in an interview process whenever I have to write code and there isn't some discussion about that code - to the point that I feel it a waste of my time and a strong signal not to work there.
If it's enough for you to say that because you have a test that everyone takes and it filters your candidates so that's proof of ability, without even going into the results and asking if your test is optimizing for the correct things, there's nothing I can say to convince you otherwise.
Anecdotal, but I know about a half dozen people with experience and CS degrees who would blow your filter but can really get shit done and don't really need any training.
Hiring is hard and the real shame of this industry is that collectively we don't approach this problem with the same level of rigor that we do everything else because by and large we consider this sort of work to be beneath us and not worth a significant investment of our time.