I applied in-person. The process took 1 day. I interviewed at Trader Joe's (Hartsdale, NY) in Sep 2011
Interview
The interviewer started by asking why I wanted to work for Trader Joe's. After I told him about being a longtime customer we started talking about the food. He emphasized that it was a fun atmosphere. He also told me there was a good deal of physical work involved and asked if I was okay with that. He said there may be another interview, but I was hired after one 1:1 session.
Applied online and had one in person interview with the captain. It lasted maybe 10 minutes. Got a call a week or so later that I got the job. Very fast process.
It's two to three interviews, the final with the Captain (or highest manager) of the store. The interviews are largely to get to know your personality and how well you would do at customer service.
The interview process was absolutely wonderful! I didn't feel stressed or nervous and it felt like I was just chatting with a friend! Trader Joes is a great company and the interview was great.