Phone call and then Group interview in their main offices in Madrid. Once you go through that they just make the offer in a few days, there is no one to one interview.
I applied online. The process took 1 week. I interviewed at Zara (Londres, Inglaterra) in Jan 2019
Interview
Applied online on the Inditex website, then received email for an interview by the managers of the store. They showed and explained to me the tasks that would involve when working.
Interview questions [1]
Question 1
What are your hobbies? Why do you want to work for us?
They ask why you want to work at ZARA, what your hobbies are, how much you know about the company, where you see yourself in 5 years, what your strenghts and weaknesses are.