Really long application process, and the interview day lasted pretty long as well. I had <10 people at my interview day, so luckily ours didn't stretch out too long. Everyone gave 5 minute lessons (I actually did not finish my lesson entirely, was cut off in my final group activity), and then there was a group "roleplaying" activity in which you were presented with an educational dilemma and had to discuss it with your fellow applicants, and then the interviewers talked and presented opportunities for questions. Then, you signed up for your individual interview session.
The individual interview lasted about 55 minutes, and in it I was asked to expand upon my resume and my pre-interview activity (if you are currently applying for TFA you should know what this is), and otherwise had a great discussion with the interviewer. We talked about why I'd chosen the volunteer and job opportunities I'd taken on in the past, what my roles were like, and asked to talk about the numbers (statistics of achievements I'd accomplished in my jobs) on my resume as well.
Make sure you practice, practice, practice your lesson. Leave yourself an extra minute for questions you WILL receive, because when you're up there and you're nervous, you're gonna stumble over your words and take longer than you planned. Make sure you've incorporated effective activities that will help you gauge the understanding of your "class."
I made sure to give thank you cards to the interviewers. Also, you're not competing with the other applicants on your interview day. Do your best to support them and help them be the best they can be, because all of you could get in if qualified. Ask easy but significant questions during their lesson so that you won't throw them off but give them a chance to show off their improv and question-answering skills, converse with them while waiting for your interview to start and get to know them, make sure you take the time to listen to everyone's opinions in the role-playing activity.
In the end, it is actually quite fun. I met some great people, made some new facebook friends, and got a chance to be a part of a rigorous process that makes other job interviews I've had seem like cake. If you care about education equalization, this is your chance to do something great. However, if you only want a resume builder, I'd suggest looking somewhere else. With the confirmation of Betsy DeVos, America's public education sector is going to need as many competent, experienced, and passionate teachers we can find to ensure that our children will be armed with the knowledge they need to succeed. For all the flack TFA receives, I do believe that that is still their mission.