[EnderMB]

As standard, yes, it would be a bad idea for a normal recruitment agency to do this.

My problem with recruiters is that they are salespeople. That's all they are. They take a CV, and they sell it to someone, and ultimately it doesn't matter if the person is good or bad, all that matters is that sale. As you've rightly said, they don't know enough about the technical side to provide a technical review.

So, why not have a separate team wholly dedicated to technical vetting? Have the process be completely open to employers, so anyone looking to hire a developer can see exactly what is to be asked of their prospective employees. If the questions are bad, the employer can say so and a qualified developer hired by the recruiter can tweak the process.

It's essentially adding a separate team to the recruitment process, one that builds a robust interviewing framework. They don't need to be full-time either. They can be working developers on a freelance basis that have gone through the interview process, and know what questions to ask based on the stack an employer is using.