I initially applied for both a Research Engineer II job and a Software Engineer II job. I applied online, and was also referred by a colleague's husband a week or so later. They decided to interview me for Senior Software Engineer, Senior Research Engineer, Software Engineer II, and Research Engineer II, because they weren't sure where I would fit the best - the job that I was officially interviewing for was Senior Software Engineer.
The phone interview was a conference call with two people. It lasted about half an hour and had pretty standard talk-about-your-background-and-interests questions. Shortly after that, the company scheduled an in-person interview, but it was delayed by a couple of weeks because it was the holiday season and people were in and out.
The in-person interview was very long - I ended up talking to 10 different people in two different groups, although in a couple of cases I was talking to them two at a time, and I also had to give a 45-minute research talk with questions period afterward to all-comers. The whole thing lasted about 9 hours and I was ready to fall over from exhaustion by the end of the day even though the actual difficulty was average.
The actual interview questions were pretty standard for technical positions at research firms, a mix of technical questions, and discussion of my past projects and interests. Everybody was quite nice and helpful and the people who had me for lunch took me to Legal Seafood in the mall.
I asked most of my interviewers what they liked and disliked most about the company. This part of BAE used to be a small research firm that was acquired a few years ago, and everyone who got this question, without exception, told me that this office had been allowed to maintain its own culture for the first few years after the acquisition, but now larger BAE culture was conspicuously storming the gates, and that this was the thing they disliked most. I don't know what it was like before, but on the whole I was very impressed with the people and the local office culture. People were smart and seemed interested in what they were doing.
The research talk was relatively early in the day. Neither I nor the attendees could get my laptop (a Thinkpad) to play nice with the projector, so we had to find a flash drive for me to put my presentation on, so that it could be transferred to a company laptop. By this time I was starting the talk 15 minutes late and was very stressed. The talk itself went well. People were polite and didn't interrupt me. There were two or three questions asked during the presentation, and seven or eight during the question session afterward. All were clarification questions - nobody challenging me. There were 15-20 people in attendance, which I was told was a larger-than-usual crowd. I got compliments on the presentation all day, and people who hadn't made it to the presentation telling me that they'd heard it went well.
The last person that I talked to was from HR, and she said that she'd been getting feedback all day as people completed their interviews with me. She said that it sounded like I was better suited to the Research Engineer track than the Software Engineer track (which I agreed with), and discussed benefits and my impressions of the company with me.
I heard from them two weeks later. I ended up getting turned down. I was told that they had been generally impressed with my abilities, but that I wasn't development-oriented enough for the Software track and didn't have advanced enough educational credentials for what they wanted for these particular Research track positions (I'm a part-time grad student, so I'm working to remedy the lack of advanced degrees). Oh well. It was a good experience and prepared me for subsequent interviews where I had to give a research talk.
A bit of advice: If you have to give a research talk, bring your talk on a flash drive, even if you're bringing your laptop. Your laptop might do what mine did and fail to work with the projector, and the stress brought on by technical problems is no way to begin a presentation.