I applied through university. I interviewed at IBM
Interview
First round - 1 case interview with a Senior Manager. Second round 2 case interviews + behavioral with partners and senior partners. Fairly straightforward process and streamlined once it gets going.
I applied through an employee referral. I interviewed at IBM
Interview
Had three phone calls screening interview, half an hour each. Slotted on-site interview. Questions include solving business cases (choosing between two business plans), statistics (Bayesian) and data science (clustering and classification).
I applied through an employee referral. The process took 1 day. I interviewed at IBM (Armonk, NY)
Interview
Brief screening interview (in person) followed by full-day on-site interview. Interviewed with four consultants who asked a mixture of business, statistics, and brain-teaser type questions. The day culminated with an interview with the section head who did a brief and fairly easy case-style interview.