I applied online about seven years ago. It took a bit before I was contacted. I received a date to take the AT-SAT, which is an aptitude test for controllers. I scored well on the test, had an interview and took the MMPI-2. I was offered a location and accepted (If I had known declining was an option to receive another location, I would have). Shortly after, I was given a date to show up for training in Oklahoma City.

Structured, everyone gets the same opportunity. There is basic questions that interviewers are instruction not to stray from. Study the position you want and ensure your able to fill 45 minutes of interview space because after the questions your the one speaking.