As it is with most pharmaceutical company intern hiring processes, the process is generally not a short one. Applied for the job in January and got notified for an interview in March. Was a phone interview, and the interview itself wasn't too bad. Being that this was my first ever phone interview, I was a bit nervous and didn't know what to expect, but I really can't say anything negative about the experience because my interviewers were easy to talk to. Ended up being about 20 minutes, and I spoke on previous and current research projects. Heard back after about a week and a half. As a disclaimer, I know absolutely no one that works at Merck, and applied for the job online via their Careers section.