Plug Power Lean Manufacturing Engineer interview questions

Had a preliminary interview via Skype first which was with an HR rep and then the hiring manager. They used the interview to determine what "level" of engineer I would be in the role. Then came in for a second round of interviews where I had 4 30 minute interviews with engineers and managers. They asked pretty standard questions and told me about the environment I would work in. Although I thought the role might have some good learning opportunities involving six sigma, the compensation was simply not competitive enough for me to accept the offer.