Took an optimization test before meeting on site then was called in for an in person interview. Met with the hiring manager as well as another technical employee, both were friendly people. Proceeded to the interview room and was asked a range of technical and non-technical questions. Fairly in-depth lines of questioning, which was expected, I even ended up learning a thing or two. Interviewers were very calm and passive in their style of question delivery (meant in a good way); I never felt I couldn't ask a question to further explain or understand the desired answer. Tough interview but a great experience overall.