It happens in two stages via Skype. In the first stage, an interviewer asks you a basic question about yourself, your work experience, etc. After that, You will get materials in the email in order to prepare for the next round. In the second stage which will take place on a different date, you and 5 -10 others will get a 20 minute group preparation with one of the teachers working there after which you will conduct two 15 min. mock lessons with two staff members who will pretend to be students and you will be notified about the result of your performance. If you pass, the last stage is orientation which is taking place an hour after your second mock lesson where you and the others who passed will receive further instruction. It lasts for about an hour.
For the demo lesson, read this carefully, they chose a lesson from there original materials , and you suppose to conduct the lesson like for real , unfortunately they don't consider that you never saw the lesson before, normally you prepare the lesson before class, this is not the case in demo class, as a result of that, you also discover the lesson with the student , you have also to respect the flow of how to conduct the class and have an eye on the time , any mistake you are out , I failed my demo and it was a pleasant experience . I hope this helps you guys