3 step process: initial sit-down interview, a half day of shadowing other employees and getting to know the salon, and finally a technical interview (full highlight, retouch, cut, blowdry/style.)
The first interview is your typical Q&A session, no difficult questions, very easy to turn into a conversation. The shadowing day, you will follow around other associates to learn what they do and where everything is in the salon. If that goes well, and it's hard for it not to, then you will perform a technical interview. You must bring a model for this, but they will provide a mannequin for the part of your technical that you need one. They will also assist you in mixing color formulations with their Wella line, as they don't expect you to know it well.
The associate position is their immersion/apprenticeship period, which lasts about 8 months, before they take you on as a full time stylist (or a stylist at all, actually.) You will assist other stylists and do janitorial duties. You will attend weekly classes and test out to work on the floor based on timing more than skill.
Once hired you will take a learning type test, the kind that gives you a number 1-4. Everyone at the salon takes this very seriously and constantly refer to their numbers to explain personality quirks like a middle school girl with an astrology book.
