I applied online,and got a call from HR in 5 days. First round was in person with HR and a Senior Strategy consultant. Very pleasant experience. HR asked me to go through my resume, some detailed questions on my experience. The Senior Consultant asked me on my interests and why I wanted to join interbrand. I was then administered a 45 minute analytical test-consisting of questions around Data interpretation, Critical reasoning, Logical reasoning etc-which I know I did quite well.
Got a call for a second round within 24 hours. Second round was with a Strategy Director and Strategy consultant. The Director was an Analytics PhD, and asked really high level questions.
The second interview with the Strategy consultant was a 15 min exercise.