Back in 2008 it was very in depth. There was a written test, HR interview, and a tech interview on day 1 (Day 2 consisted of the simulator evaluation).

Tech Interview:
-Coming from a 121 background, I was asked a lot about 135 operations (some 91K)
-High and Low Alt Charts
-App Brief and questions about a specific approach plate
-FARs
-Weather
-Memory Items and Limitations from the current aircraft I was flying at the time
-TERPS

Each interview lasted 1 to 1 1/2 hours. They made us feel very comfortable, but it was a thorough interview process. Only 3 out of the 14 guys in my interview were offered jobs. Study as much of the old gouge as possible. I am not sure what the new process will like, but we were told in recall class it would be similar to when we were hired.

Good Luck!!!