The process was a lot faster than I expected. Applied in October, got the invitation to do a video interview 2 days later. Did the interview and less than 24 hours later, was asked to schedule a F2F at my local airport.
Interview process took 6 hours total. By hour 4, I had received a (conditional) job offer. They start off by having you watch a presentation in a room about the airline, then they answer a few questions. They took a few people first to do 1-on-1s while the rest of us waited for about an hour to be interviewed, so you have to be PATIENT! The 1-on-1 was pretty easy, they ask general questions that they expect detailed examples for. Have a list of customer service examples (of different situations) that you can use to reply. They also make you read off a card, so practice reading things aloud so you won't stumble on your words. The first stage took about 15-20 min, then they either ask you to stay for "more details" or to leave. I got asked to stay.
Second stage (after you're brought to a new room to wait again), is a 2-on-1 interview where the interviewers are more blunt and straight forward (in my experience). Be confident, sit up, and smile! They only asked about 4 or 5 questions before they offered me the CJO.
All in all, it was great. I found that while you wait, you should DEFINITELY talk to other interviewees. Not because anyone was watching us (they weren't), but because it can really help calm your nerves. I went into the 1-on-1 a lot less stressed because I got to spend so much time joking around and having fun with the others. Get to know them-- some may be in your class if you get CJOs.
The recruiters and interviewers were ALL nice and so, so sweet. I honestly think it went so well because they were all so kind and seemed genuinely happy to be there with us. I'm very excited about my job offer and training.
My advice: all the prior questions listed on this site are incredibly helpful-- study them. Collect as many questions as you can and practice your answers for them. They don't give you a lot of time to think, so you want to be able to recall an example quickly! I studied all the questions here and felt very prepared for my interview. If you know what the FA job is, you know what answers they're looking for.
Don't forget to have fun!