The process is pretty easy, you basically send in your application and answer the question on the Interac website. In about a weeks time, you will be contacted for a phone interview.
After the phone interview, there is an in-person, group interview + presentation. This is a little sketchy, because you may be required to travel and the interview may be conducted in a hotel room because it's usually conducted by someone who used to work for Interac themselves.
SUGGESTIONS: BEFORE the in-person interview, actually WATCH and practice for the presentation part of the interview. It is the last part of the interview, and you may need to make your own props for it.