Easiest way to cut through the noise is to give candidates some whiteboard questions. This will invariably filter out some good candidates that aren't good at these problems, but you'll be left with a bunch that have some baseline competency.
Downside of this is that you still might not get, say, someone who can hack a security watermark feature into a react native camera app. Being able to solve hardest questions might not necessarily mean they can solve easier ones, or that they can get work done.