Standard online tests then assessment centre after long wait, but with regular updates to let you know you're still in with a chance. Assessors from the department were generally nice, though they don't seem to have much interview experience. Day consisted of interview, group exercise, presentation you have to take with you, and nice lunch.
Unfortunately it took more than 5 weeks to hear back, despite them saying we would hear by the end of the week. I had figured by that point that I didn't get it.