I applied through an employee referral. The process took 2 weeks. I interviewed at ZS Associates (Evanston, IL) in Dec 2011
Interview
First, they schedule a phone interview that involves a 30-minute case and a 30-minute behavioral interview. The case is done over phone and webex - it's generally pretty easy. If you pass that, you move onto the final interviews, which take place at a ZS office. This portion consists of two cases (with managers), behavioral interview (with a principal), lunch (with associate or associate consultant), and a demo (with associate or associate consultant). They really try to gauge if you are a good "fit", so try to be personable during the lunch and demos (ask questions, be engaged, etc.), and obviously try your best on the case - you have to really bomb it to not get an offer.
Interview questions [1]
Question 1
Tell me about a time when you worked with a difficult team member.
Good interview started from basics went in deep about sql python and projects as well. Did cross questioning on projects and then ended with a some behavioural questions. Overall a very nice experience.
they take an online test of verbal, data interpretation, aptitude, etc. They also ask a question which you have to reply through a video, where they will give you a random topic, you have to record a video speaking about the topic for 60 to 90 seconds.
The interview process is a bit difficult to crack. Go through your resume and be ready to answer whatever they ask about it.
Practice guesstimates and puzzles thoroughly. Be consistent with your logic in solving problems