Applied online. Got a phonecall about a week later inviting me to an interview. Had to fill in a form while we were waiting then we all went into a separate conference room for a group interview- there were about 15-20 people. We all had to go around and say our names and why we wanted to work for Zara. Then we watched two videos: one about the company and one about a day in the life of a sales assistant. We then had to say something we learned about Zara/the position that we didn't know before. Afterwards, we separated into groups and had to work out to sell some products that weren't selling well. Then we were given a problem we might encounter in work and what we would do. Lastly, we were put into pairs and had to say why the other person would be good for the job.
Before we left, we had a quick (like 2 minute) 1-1 where we stated our availability and what department we'd like to work for.
Overall, the interview took 2 hours. It was quite laid-back and all the managers were lovely. I got a phone call the next day saying that I got the job!