I interviewed over 1200 people in the last one and a half year. When I was working at the bank, I had 15 preferred vendors searching for talented engineers. Our rates would go all the way up to $150/hour. The lowest rate ~$100/hour. Since I was running the agile development team, I always knew the resource allocation, the project timelines and my team needs, whether front end, back end, or mobile (iPhone or android) developers.
I would view all the resumes submitted to me. Out of 1200, I probably phone screened around 500 people. I learned a lot through the process, especially how to manage the people aspect of the business. My phone screens was schedule for 30 minutes, although my interview would last ~12 minutes on average. I would first tell the candidate about the team, project and architecture. I refined my pitch so most of time people would be thankful that I explained everything so well. There is no room for questions so it saves time, and the candidate doesn?t go back and complain to the recruiter about my communication skills. I would then ask them if they are ready for technical interview where I would ask a couple of questions from their resume, whether they really know their stuff. I would then open up for questions at the end. Whether I like the candidate or not, I let them know that the recruiter will communicate with them, as to protect myself and the bank.
If I like the candidate, I would schedule a face to face interview. I brought in about 50 people from the 500 people that I phone screened. My team size was 15 engineers, so when the candidate came to the office, I would pick 4-5 engineers, each spending 30 minutes to an hour with the candidate. If my team doesn?t like the candidate at any point, we showed the candidate the door. This saves time, because if the first interviewee doesn?t like the candidate, there is no point going forward. We hired 12 engineers from the 50 face to face interviews on site.