My initial offer to come for an interview was via phone. The interview itself was very relaxed; took place in a fairly empty cafeteria and took only about 20-30 minutes. Besides the typical questions, one that stood out the most was a question on how you might go about measuring the traffic volume on Interstate-90, particularly as it passes of Mercer Island. I found this question valuable as the interviewer was able to get an accurate sense for my thought process and problem solving abilities. The job offer came within a few days of the interview, via phone.