I have just had my biographical interview for migration to uc. I would like to say for the benefit of people who are feeling anxious if they are due to have one, that it's pretty straight forward. There are no trick questions, it's a few random questions based on information they already have on you. E.g. date of birth/ previous address/name of benefit your receiving and how often. It was under 10 minutes. I hope this alleviates some anxiety/stress you may be feeling.