Applied online for several open positions. First call back came several months later from HR person who mainly wanted to confirm interest in position and give very brief overview of position and program. Had a second slightly more thorough phone interview with HR within a week of the initial call that included more details about position and confirmed qualifications for position (i.e. okay with carrying 50+ lbs, working outside, operating vehicles, etc.). The final interview was a skype call with an operations manager of the specific office I was applying to. Final video interview lasted about an hour and included in depth rundown of position details and several character and situation based questions.

Interview was pretty generic. It was more of a discussion as this was an entry level co-op position. Mostly the interviewer let me know about the workings of the company. My school has had a good reputation with the company so he didn't need to go into too much technical detail.