Personable rotation of potential future team members and deep insights. I had an initial PR interview, was forwarded to an interview with my direct manager, and ended a week or two later with a rotational interview between the 4-person team I'd be joining with 30 min segments per person totaling a 2 hour interview. I got word of my acceptance within a week after.
New Relic employees want to know that you'd be excited to work with them as much as they'd be excited to work with you. And they communicate all of that. I found that you are at total freedom to ask questions regarding work life, culture, etc. In fact they encourage it. New Relic is maturing fast, but they continue to maintain that family-feel both before, during, and after the interview process. Ask questions and get a sense of whether you'd enjoy working in the New Relic atmosphere, and you will be set up to succeed in whichever position you may end up in.