The process I went through was a bit out of order because the CEO wanted to chat with me on the phone before leaving on a business trip. He was very friendly and knowledgeable and asked me some general question touching on technical topics like CoreData, GCD and my experience with them, he also asked about my motivation getting into the field and about my rather colorful work history. He told me about the company. Overall I was impressed with what I heard.

 A few days later I got a call from the head of engineering, he told me a bit about the interview process and arrange a time for me to come in. On the day I came in and had a friendly interview with the head of engineering again touching on lighter topics. After about 30min he brought in two of the iOS Engineers to continue the interview. They asked general question, took a look at my apps before moving to the white boarding challenge. The challenge was very straight forward and low pressure, it was mostly syntactical questions and there were no curveballs. When the engineers left the head of engineering came back in to finish up the interview and explain the rest of the process. Later that day they emailed me an online coding challenge composed of 4 logic questions. The following week they called me in for an in person interview with the CEO, again no curve balls, just a good conversation with normal HR questions after which he looked over my apps and told me more about the company. He was very positive and said that if my references were good then they were bullish about hiring me. A few days later I got the call with the offer and started the following week. Overall they had plenty of opportunities to trip me up or be difficult however they were clearly focused on moving forward smoothly and vetting for a good team member.