OPNET AppTransaction Xpert interview questions

Applied online. Received a pre-screening interview than set up a phone technical interview. Was asked basic networking and coding questions. Then took a one-hour coding test in which I had to design a system to accept planes that are ready for take off and allow one at a time to take off based on priority. I did this with four different queues, each having a different priority. Reviewed this with a senior engineer. Asked performance questions, how I could have improved it, how I would have used a different data structure. Waiting for next step.