They contacted me by email to give them a call so that an "informal" interview can take place. Based on that interview, they schedule you for another interview but this time it will be the "technical" part of the interview.
I was given a study guide in PDF format through email to study from to prepare for that interview. You are given about a week to prepare so I want to say this is to determine whether or not you are capable of learning quickly on your own and capable enough to undergo their 10-12 week training program. I did not take the technical interview since I declined the offer because I was having 2nd thoughts and personal reasons on relocation.
I had no problems with the interview process but personally I think this opportunity is only suitable for those who truly desire to be independent and away from family. If you prefer to stay close with the ones you love, I wouldn't recommend this job. If you feel you are capable enough to take the risk and challenges with this opportunity, and truly know what you want in your career future, then by all means go for it.