KLA Control Engineer interview questions

The phone interview was mainly about my background and role responsibility of this position. Then, I was scheduled to have the onsite interview. It's a full day long, seminar + interviews with 6 engineers there (~30 mins each). They described their hardware system and ask me how to synthesize a controller for position tracking purpose. Describe the controller design procedure. I also got a question regarding problem solving at customer site if the controller didn't work properly, what should you do? Other than that, the question related to my background and some technical issues they are facing with. I have a great experience of this interview.