Fairly smooth, explained well, took a while to move between stages but this was warned as possibility during busy times of year and I applied near tax year end so I wasn't in any annoyed about this.
Fairly similar to other accountancy firms, online tests, phone interview and assessment centre.
Online tests were simple enough, SJT as part of initial application is standard. Then online numerical and verbal tests are simple enough, more emphasis on time than difficulty.
Phone interview was slight harder than average in my experience, be prepared for competency based questions and have some current news or commercial awareness ready to talk about, follow up questions will be part of this so do your research and try and relate back to mazars as a company, explaining why it's relevant to the company and industry.
Assessment centre was a bit odd, as only 3 people were there, although 6 were expected. Apart from this the management and interview team were outstanding. Extremely friendly and put all of us at ease the whole day, I can't compliment them enough.
The day began with a presentation from the team about the company and what the role and assessment day itself would involve. Then we began a group exercise, consisting of some proposals that we had to evaluate against a given budget. Some ad hoc proposals and memos were thrown in half way through so beware of this. The time given was about 20 minutes, during which you must choose what proposal(s) you are going with and why. The team will ask you each some questions on these. You will then be asked to make a short presentation on this.
My advice for this stage would be to be outgoing and try and take the lead, but not direct, the exercise. Make sure you are vocal and explain your ideas logically, always giving reasons. Try and get others involved as well, make sure it's not just you throwing non stop ideas into the pot.
After this there was a numerical test, which was simple given the time, and a short written exercise in which you had to write an email to try and get people to attend a meeting.
After this there was a one to one interview. My interviewer was a senior accountant and she was lovely, absolutely brilliant. The most relaxed and enjoyable interview I have ever had without doubt.
Lastly, some lunch was provided along with an opportunity to talk with the management team and current graduates.
Overall very good experience and would recommend applying