Only a single round of interviewing -- takes place on-site (tour of the Raytheon's building and then interviewing the next day at the hotel). Candidates appear to be selected based purely on resume screening (since there wasn't a first-round interview).

Generally, the interview process seemed pretty smooth; Raytheon did a great job organizing the on-site visit/interview. Workplace seems decent; lots of fancy equipment; as may be expected from a defense company, the safety and security procedures are somewhat high.

First day involved a welcome brunch, tour of the building, and a somewhat informal dinner where we could talk with some of Raytheon's current employees (mostly the managers conducting the interviews).

Second day involved interviews, and the flight back home. It looks like each of Raytheon's departments screens resumes, conducts interviews, and makes offer decisions separately. Interview is mostly non-technical (no puzzles or "quizzes", etc).

Questions were mostly "soft technical" questions.

For instance, interviewers looked through my resume and picked random random topics off the resume as starting points for the conversation. (e.g. "Tell me more about the chess AI program you wrote.")