I was contacted by a recruiter via LinkedIn. We proceeded to a brief phone call to talk about the opportunities at AppNexus and my objectives. A 40min phone interview with a manager followed in the next days in which I was asked about my experiences and we talked about the industry, the company and the job description/requirements.
I was then asked to come to a half-day of interviews at AppNexus in Paris. I had 3 very different physical interviews and 1 video interview. The first one was a classic interview based on my resume and past experiences. The second one was a behavioral interview. The video interview was a high-level technical interview in which I had to use the white board to answer questions about the online advertising industry and how it actually works. The final interview was a problem-solving interview during which I had to solve 3 logic problems and 1 short case problem. I received a feedback after each step by email.
All the interviewers were friendly and nice. The whole process took 3 weeks.