iRobot Principal Engineer interview questions

I believe a recruiter found my LinkedIn profile and sent me an email to see if I was interested. I was open to see if it would be a good mutual fit. Had an initial phone screen with HR, then another phone interview with the hiring manager, then two onsite interviews that took a half day each (3 or 4 one on one interviews lasting about 45 minutes each with other principal engineers, program managers, 1 director. Since I lived in the area the total process from phone interview to the final round of on-site interviews was about 4 weeks. Received an offer a few days later. Everyone was polite and friendly and instead of waiting for questions and then answering them, try to be personable and make it more into a mutual dialogue and conversation. I would say a good balance be to keep the dialogue 60/40 at the onsite interview. 60% let the interviewer talk and ask questions while 40% you can take time to respond and also ask some relevant/good questions. For some interviewers they may be busy about their day and may not have even read your resume. In that case be prepared to "lead" the discussions and maybe more of a 50/50 dialogue. Smile, stay friendly, and flexible. Definitely have a few good questions for the interviewer.

Applied online through company website. Got a call in couple of days from the recruiter. My profile matched (or exceeded) 100% to what they were looking for, the role/expertise required was somewhat niche. One phone interview with another engineering individual, after which I got invited for an in-person daylong marathon interview session with at least 8-10 managers, PMs, engineers. Most of the interviewers had no clue about the role or the kind of questions they should be asking (some of them accepted that when I was asked if I had any questions!). Most of the questions were based of previous experience, behavioral. The whole process was super easy, but seemed unnecessary, as by the time I got through hiring manager's interview (2nd in the day), I know I had the job. If you can talk crap intelligently, you'll thrive in interviews at this place.