I applied through an employee referral. I interviewed at RTX (Tucson, AZ) in Feb 2019
Interview
A scheduled phone call - normal process and technical questions. Low stress and semi-informal. The interviewer made an effort to connect with me. Some small talk about the area, size of the site, and general talk about the site, people, and weather.
I applied online. I interviewed at RTX in Dec 2016
Interview
One phone interview - then an onsite interview with 5 people. No hard questions - fairly pleasant affair with low stress meetings and lunch. The overall process was long but things went rather smoothly.
I applied in-person. The process took 1 week. I interviewed at RTX (Chantilly, VA) in Sep 2016
Interview
Disjointed at best. First a phone interview with 3 people, then a face to face interview. I arrived at the Chantilly office, and they the interview was conducted in a conference room that was occupied by someone else not associated with the interview. They stayed there and continued to work on their laptop. I won't apply to Raytheon again.