I had the opportunity to have an interview at Ipsos Spain. Very enthusiastic first, I was disappointed after. Indeed the contact wth the HR department was not as good as I could expect from such a company.
After a phone interview, a face-to-face interview, and a skills testing... No news! Despite reminders, the HR department didn't give any feedback nor said they were continuing with other profiles instead. In fact, I still don't officially know 3 months after...
This experience unfortunately totally influences my image of Ipsos.
The interview difficulty was average and was mostly related to the professional experience in the specific field I applied and, related to my life career and personal path.
There was a skills test about statistics reading. No preparation needed ahead, you just need to understand the global logic and then you go. Quite tricky though so be attentive. ;) Good luck!
Then, there is another round with the specific team's manager and a powerpoint presentation simulation.