Went to an Assessment Centre for the APL role on offer at AZ's site in Macclesfield. Day consisted of a Values interview (competency questions based around AZ's 5 values), a technical interview (an hours preparation for some technical manufacturing questions and a 10 minute presentation), and a standard group exercise.
Whilst I didn't get the job it was a good experience to have. Felt a bit overwhelmed by the number of assessors (nearly twice as many as candidates there) and am still awaiting feedback. Would reapply if given the opportunity seems like an amazing role to get.