My application had to be vetted through the civil service process and I applied directly to the library too. Only mail-in resumes were accepted. The panel consisted of three librarians and three others. Because the panel seemed so bored I had the sense this was one of those cases where they knew who they wanted to hire but were required to post the position anyway. For what it is worth, being interviewed by clerks and not someone in HR or the department managers was kind of insulting.