So guys i just wanted to share my experience with you for my application in Morgan's Stanley operations division in Glasgow. I applied late June and received an email two weeks after from HR telling me that they will call me to discuss my application. They called me the next day and asked me questions like why MS, why Glasgow etc. Then I was invited to another telephone interview with an operations manager. It was a competency based interview so make sure you are aware of the STAR technique. Two weeks after my phone interview I was invited to an assessment centre. The AC consisted of two 45-minutes competency based interviews and a group exercise. The interviewers were senior employees of operations. Don't worry about the interview everyone was friendly and there are no technical questions. The group exercise was easier than expected and included discussion, presentation and QA. At the end we had a 5 minutes interview with someone from the HR to evaluate the application process.
Overall, everyone was friendly, all the managers were approachable and there was a really positive culture there. Still don't know if I will be offered an offer (since the AC was yesterday) but I'll let you know when I hear back. I would highly recommend you to apply for MS, it seems a great organisation. The only downside is that I had to travel from Greece on the last minute to attend the AC.