Timeline: the hiring process took almost three months. I was contacted for a phone interview two weeks after applying to the position online through Sandia's career website. The onsite interview was confirmed one week later, and took place four weeks after the phone interview. A verbal offer was extended seven weeks after the onsite interview. This longer than usual timeline was due to the holiday season and vacation. Communication and feedback were excellent throughout.
Phone interview: this was with an engineer with experience in the position and lasted about 30 minutes. It was very straightforward and casual: we discussed my interest in the position, qualifications, experience, biggest challange(s) and success(es) in my Ph.D. work, some details about how the group is composed, and life in Albuquerque.
Onsite interview: this was a full day, lasting from 8:30 - 4:30. First was an hour-long HR briefing with a few other interviewees at Sandia that day. I was then escorted to the group's building and gave a one hour seminar (50 minutes presentation, 10 minutes Q&A) on my Ph.D. research. This was surprisingly well attended by about 15 Sandians, about half of whom were not interviewing me later on but were just interested (this seems to reflect the atmosphere of the lab - learning and growth are definitely parts of the culture). The rest of the day consisted of a 30 minute 1:1, a 2 hour lunch with managers, two 1 hour 1:1s, and a 1 hour 8:1 group interview. Overall there was great balance between personal, technical, and behavioral discussions. I was given opportunities to show my expertise, sell my character and skills, and ask questions. All of the interviewers were positive and eager to both hear and talk about my fit within the group. I felt like they were selling Sandia to me as much as I was selling myself to them (what a relief this was!). The group interview was the toughest part, but that was expected: thinking out loud is hard for me in front of a group of people, but they understand it is stressful and helped me through parts where I struggled.
Overall: the entire process was a great experience. Logistical details were handled well and travel was easy.