I was first contacted for an on-campus interview through our department resume book. The interview was with two alums, a day after an informational session, and covered my PhD work and some behavioral-type questions. Both recruiters were technical staff who went through the Career Development Program (CDP), an 2-3 year rotation program, and were very friendly. They kept me updated on their selection timeline and I was contacted 1.5 months later by HR to arrange for an on-site interview.
The on-site interview at company headquarters was a tightly-run 3 day affair. The first night included an "informal" dinner with one of the recruiters that sponsored my visit and a technical manager. I was made to feel welcome and given the chance to ask about my interview schedule. The interview day started with an hour-long seminar followed by five one hour interviews with individual managers from different, but relevant, areas of the company. It also included lunch with two current CDP scientists as well as a short meeting with an HR representative at the end of the day.
The interviews were very cordial. Topics ranged from technical questions regarding my PhD work to overviews of their specific business areas to what I could expect career-wise if I worked at the company. As a scientist, I found the work in the company to be interesting and thought the CDP rotations would be a great way to learn and network. Based on interactions, I would definitely recommend the Air Products to prospective employees. Two weeks after my visit, I was contacted by HR with an offer and one month to make a decision.