Friendly and professional. Initial call with HR/recruiter, then scheduled an in-person. Met with same recruiter, CTO, lead dev, and two other devs on the team. Technical interview at times felt more conversational rather than "being grilled," but you still had to know your stuff over a broad range of topics. I expected to get attacked by ds/algo problems, but I enjoyed this format instead. No obscure trivia-style questions or surprises either -- everything covered felt fair game. There was one question where I misunderstood the question and forgot the exact syntax, but the interviewer seemed cool once he realized I knew the concept he was getting at. Can't really "prepare" for this interview outside of being able to communicate what you know, and being able to talk about your own experiences. This is a two-way street, so it's on you if you don't convey yourself well enough. I felt like they did their part in trying their best to get an honest feel for my abilities and what I knew. Didn't get the offer, but it was an overall very positive experience. AP was kind enough to give the rejection in a timely manner.