The types of engineering that I do are not the most technically difficult. But it is a very small piece of the engineering pie, so there are not many out there with my combination of skill-set and education and experience. That is, I may not be representative of what the client probably needs in the long-term, as I was hired by the client to solve a particular and unique problem.
So I typically screen for someone under 45 (I am over 60) that has done and is interested in certain types of math, programming, test, and hardware design. This is how interviews need to be structured - and just devolving algorithms and citing random information and doing circuit node calculations from schematics will be less likely to identify the engineer that you need.
As for the problems cited by the writer - they are relevant, but are structural and should be self evident to anyone out of school for more than one or two years.