And in my experience listening to auditions over the last several decades, what you have now is a bunch of musicians who can only do what's on the test. When you try to plug them into an orchestra, they are completely fucked.
My experience interviewing and hiring tech people is that this is one of the worst possible approaches. Anyone who needed to could figure this out. It's not relevant. What you need to figure out in an interview is if the person is curious enough to find the answer.
I don't ask for code or algos in my interviews. I ask about the person. What's your favorite programming language? Why is it your favorite? What do you not like about it?
What's the project you are most proud of? What was hard about it? What made you happy? What did you find challenging about that project?
These are 100% totally humane questions that tell you everything you could possibly need to know about a candidate in about a half hour. Maybe less.
If you can't figure out if this person is technically competent from this set of questions then you aren't competent to interview or hire.
Interviews don't have to be only about how good you are at interviews. They could be about trying to understand if the person would be good at the job and fit in well with the team.