Another recommendation - be sure to give a feedback after the interview. This will supplement your requirements, and with subsequent candidates more likely everything will turn out, as the contractor will know that it is especially important for you.
It is unlikely that a normal vendor will try to slip a jun instead of Midl or Signora and risk ruining relationships, and also spend strength on such a microenjection. Plus, this is no different from the situation when a person comes from the market and says that he is a Signor. The risk that such an unskilled employee will slip through is inconsistent from the option from the market, and in the interview it will also be clearly seen, including the attempts of the vendor in advance to tighten the knowledge of the specialist under the profile of the request.
