It was a long process for sure-- I applied in July, a week or two later they emailed me asking that I fill out a questionnaire. A week or two after that I was invited to do an online interview.
The online interview is awful, not going to lie. They prompt you with a question (there are 5 altogether) and they start recording you immediately, so there's no time to think or prepare your answer so you kindof just end up blurting out a response... Or I did anyway. All of these questions are about how you behave in certain situations-- talk about a time you went above and beyond for a customer, talk about a time you disagreed with a coworker, etc. For these you're supposed to use the STAR method (situation, task, action, result). I felt terribly awkward and flustered, but apparently I did ok because they invited me to interview at a "Blue Review" about a month or so later!
The Blue Review was AWESOME. There were about 50 or so of us there, they did a presentation that went into more detail about the job, compensation, perks and benefits, all that stuff to know (be sure to take notes during the review, it's on you to remember this information and they won't go over it again if/when you're offered the job), a couple of group activities/tell the group why you want to "go blue" and then we broke off into individual interviews. I did an initial interview with a recruiter and a member of the inflight team, then was asked to read a mock PA with a different inflight crew member. Then they did a followup interview with two members of HR/recruiting to make sure I was ok with certain challenges of the position/that this would be a good life choice for me. It's an all day process just because there are so many people interviewing, but a lot of the time you're really just standing around waiting to complete interviews. During this time make sure to be friendly/chatty with those around you, you're being watched constantly. Oh, and definitely DON'T LOOK AT YOUR PHONE. AT ALL.
A recruiter called two days later to offer me a spot in the November start class, which I accepted. From there, they ask you to fill out a pretty extensive background check including your employment history and all the places you've lived in the last 10 years. They also send you a drug test which you must complete within 48hrs of receiving. Something to note, you don't receive a formal offer letter until these things clear and you're within a month of your start date, which is a little scary... I'm confident I will pass these and everything will work out as it's supposed to, but still a little scary to give notice without a formal offer letter.
Anyway, best of luck to anyone else applying/interviewing-- hopefully this account of my experience has been helpful to you!