Challenging, two Skype interviews and an in person practical interview. They would have you open their book and guide through how you would instruct on a problem you might have never seen before.

Apply online, then fill out quizzes based on your subjects you want to teach, then you get email for instructions to watch video to prep for interview (read that and take notes), then take skype interview and they tell you in the interview whether or not you get the job or not.