These questions are not made to be difficult and should be easy to a true mid-level Rails developer. The point here is to see how confidently they carry themselves. Candidates should get kudos for asking good questions. If they go off the deepend, try to steer them back to the objective. If an interview is going poorly, it's OK for you to step in herd them in any particular direction. A poor interview is not necessarily a sign of a poor candidate, use good judgment.
- Should be able to converse and gather requirements effectively