I applied online after seeing the vacancy at a jobs fair. There's an online test, which if you pass, you get invited to pick an interview slot. Because there were a lot of applicants, it was kind of a mass interview. On the day of the interview, myself and several other candidates had been invited to watch a video about the company and listen to a presentation about its ethics, history, and the interview process. We were then taken to a hall, where a lot of different interviewers were sat at different tables, and we were all sent to a different interviewer each for a one-on-one discussion. It was fairly casual, nothing to worry about, if you are the type to worry about interviews. My interviewer was really personable and friendly.
Originally, I was put on the reserve list after the interview: they accept so many applicants, deny others, and then for applicants who they liked but didn't have roles for, they keep you on reserve for 16 weeks. I figured I probably wouldn't get a job with them after all, but after about a month, I was phoned by somebody from the store I had interviewed for, and they wanted to offer me a role. So even if you do get put on reserve, you never know!