I applied through an employee referral. The process took 1 day. I interviewed at Cornerstone Agency (New York, NY) in Dec 2015
Interview
I had two individual interviews with an associate and then with a principal. Both interviews last about 45 minutes, with an introduction on Cornerstone, then a discussion on my background, then case discussions and finally a Q&A session.
Interview questions [3]
Question 1
Why are you interested in us/economic consulting/Cornerstone?
They gave me two cases they have worked on, and we discussed how to solve the case. They offered details on the cases as well as answered any questions I had. I proposed a strategy and then we discussed more details.