They almost always vary by division/practice, but they are usually taken from a pre-prepared set of cases rather than tailored to each individual. They may or may not vary by experience/grade level - sometimes the same case study is used, but more senior candidates are expected to perform better, or focus more on the relationship management rather than the delivery aspects of the case. It all depends on how many assessment cases are available to the interviewer on the day, their personal preferences, and whether they've prepared (i.e. if they didn't have time to review your background they won't be giving you a tailored case).
