The phone assessment were typical "tell me a time" questions, and were very relaxed - they give you time to think and answer. The assessment centre was very well thought out - I was interviewed by two people and also had a group exercise. The interview was based on the key traits that they are looking for in an employee. The group exercise was standard - given a simple problem to solve as a group with no clear solution (answer was up to interpretation) and we were assessed on how well we could work together on a problem. They are looking for good mindset rather than technical skills as they want someone that is teachable.