Extremely fast interviewing process. I applied online and heard back within a couple business days, having had the initial HR phone screen later that week. Two phone interviews occurred in the two consecutive following days, along with a video chat with the head pricing analyst to assess my aptitude and thought process for a case analysis. I was offered the role the very next day, so the entire interview to hiring process took exactly one week. Not bad at all.
Due to being a long-distant candidate, I was unable to accept the summer internship position, which was an incredibly difficult decision to make given the conveniently rapid process, location, and personalities of the people I interviewed with. Ultimately, I gracefully declined the offer via e-mail, and while I didn't expect a response, acknowledgement of my desire to maintain contact so we can revisit this next year (when I graduate) would have been nice. I guess it's just business as usual, as they say.