That's what the bloody technical tests are for!
If you're giving those out, on top of a technical verbal interview, and still saying "well, we still don't know if they can even build a CRUD app with our stack", you have a broken hiring process!
I can understand the difficulty in choosing the right questions for the limited time we all have to interview to extract the maximum useful amount of data about someone. And that there's a lot of debate about which questions are right ones to ask. But a technical test that represents the basic unit of usefulness to your company is bare bones stuff.