I won't go into too much detail about the exercises in the assessment centre as they were very keen for us to not discuss what happened with eachother, but it's all fairly standard: a group exercise, a couple of brief individual exercises, and an interview consisting of you presenting your dissertation followed by a formal interview. The interview was mostly HR led so not too much about the specifics of engineering, but it is conducted by both a HR member of staff as well as an engineering member of staff so it helps to swat up a little bit before hand. Overall a good experience though, nothing too tricky, nothing boring, and the Leonardo staff were at pains to make us feel comfortable and settle any nerves. Nothing was designed to catch you out.