I applied in-person. The process took 2 weeks. I interviewed at Trader Joe's (Philadelphia, PA) in Jun 2015
Interview
On the spot, casual screening as soon as you hand in your application, which was nice. From there they schedule a follow-up interview where you sit down with a mate and discuss your motivation for working there, as well as what makes you an interesting person. They don't want robots. They give you a lot of room to fit your niche.
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.