Applied online, did some tests, had a telephone interview and was invited to an assessment day. Assessment days have mixed groups of candidates that may be going for different jobs but the manager of the job you applied for will be there. There was a group exercise, where the end result does not really matter, it's more about being a good communicator, pitching in useful information and generally being useful to the task at hand. I also had two interviews, with mostly competency based questions. There was also a presentation to make on the day and present. Overall, you need to be confident, quick at reading and analysing data to deduce meaningful information, and be friendly/show your personality without being unprofessional.