I had to Pass written test. Then an oral interview was given. Interview was given to nine other applicants. Top Three high score applicants were chosen. One random alternate was chosen

You must know everything about the office your are interviewing. Do your homework. You can not walk in and expect to get the position. Be honest, if you do not know the answer, be honest with the interviewer. Do not BS them.

Very time consuming and difficult , most of the time you must start from low level positions.