There were multiple stages, first a phone interview, followed by a written piece (about a page) on a choice of topics related to some of their sectors (eg healthcare, economics, technology), followed by an assessment day, followed by final interviews. The assessment day had some reasoning exercises and a presentation. Generally they were friendly and helpful, although there were some issues with things happening as scheduled. For example my first phone interview they missed and I had to reschedule it. Also the process was quite lengthy.