I had two interviews with Lutron and both of them were technical, but I had not been informed that they were technical. The people interviewing me did not care about my personality and only about my ability to have memorized equations.

Initially, you have a phone interview, then an on site interview. You start your day with a tour. The interview took 7.5 hrs; lunch was included. You are placed in a room. Throughout the day various people enter and ask you job related questions. There is a test.