I went through the interview process last summer, and it was mostly technical questions with some HR questions. The technical questions were actually kinda difficult. One question that stuck out was can you do a parallel ILS when the runways are 1500ft apart. Other questions like holding speeds, minimum altitudes, approach lights, medical requirements, instructor qualifications, endorsements, etc. Very picky on IFR procedures, endorsements, and qualifications. They will ask you emergency procedures for an aircraft you fly as well. I passed and was offered the job but I took a better offer.. Most people in my Stans class thought they bombed the phone interview(including myself) but were still offered the job. They where desperate for instructors 6 months ago, and I am sure they are now.