I applied through university. The process took 2 months. I interviewed at Wacker
Interview
I received an email to schedule an interview within a few weeks of applying for the job. It was a phone interview with the departmental technical manager and one other employee that I would be working with directly. Very relaxed interview. Typical questions!
I applied online. The process took 2 weeks. I interviewed at Wacker (Charleston, TN) in Apr 2016
Interview
Meet in a room with three engineers. They ask you questions about projects you've worked on and what you've learned in school and about who you are, as they want you to be someone they will want to work with. Fairly laid back, expect roughly 30 minutes to an hour if you get real chummy with them. Just show that you are willing to work hard and can describe things fairly well. There are also the very typical interview questions that you get with a quick online search.
There may also be a second interview over the phone where they ask you basically the same questions with different people. Your mileage may vary.