This is the 'gatekeeper' interview. Do not let the CTO (Pat) fool you (he comes off as very friendly and helpful), but he is very much a wolf in sheep's clothing and is looking for reasons __not__ to hire you. You must impress with enthusiasm and (especially when applying from abroad) you must make sure that he understands your motivation for the job... he makes it more difficult than it needs to be, because he will not ask these questions directly (or mention that mind-reading is part of one of the skills required for the job... lol), so make sure you prepare for behavioural-type interview questions. This will be the hardest part of the interview process, do not underestimate this interview or him.