The whole process was three stages. the first was a 1 hour phone interview which included competency based questions and a role play. The second stage was a face to face meeting which lasted 2.5 hours. This was made up of further competency based questions, a Gartner 'articulation' which is what you know about Gartner and then finished with another role play. The final stage was a panel interview- mine had 5 present but ordinarily they only have 3 present. The final stage lasted 3.5 hours which had the same format as above- competency based questions, what the candidate knows about the company and role and a role play. In the final stage you also get to spend 30 minutes with someone already doing the role.