Look at past experience, and ask the candidate to talk about that experience to verify that they aren't lying.
If someone has 5 years experience working at Google, and they can talk coherently about technical aspects of the projects they worked on, there is no reason to ask them to code on a whiteboard.
The way it currently works is this: I see you have a CS, degree and 10 years experience at a well known company. Excellent. Now you have 2 eggs and a 100 story skyscraper. Tell me the minimum number of egg drops you'll have to perform to discover the minimum height that will break the egg.
Every engineer no matter how experienced has to answer questions like they just left school yesterday, no other industry does this.
>Personally, I know that to be false. I have worked with incompetent engineers, who literally couldn't code FizzBuzz.
99 times out of 100 you could catch that engineer by talking to him about technical aspects of past projects he worked on.