Integral Ad Science Network Engineer interview questions

I applied online and was contacted by the recruiter, who seemed quite friendly, and set up an interview with the director of infrastructure team that afternoon. It lasted 20 mins and he asked me to speak with his team to go through more technical questions. That was organized the very next afternoon. It was an hour-long Google Hangout interview where two people interviewed me. They asked me a lot of technical questions. I answered all the questions correctly that were asked by the first person interviewing me. Most were what I knew and learnt from my internship and CCNA. The second person who interviewed me was a little tough. He asked few basic stuff initially but then went deeper into it, which confused me a little. But I still managed to answer most of them more or less. Overall, I felt I answered almost 85% of the technical questions correctly. I was aware of the fumble that I did for the remaining 15% but I didn't think it'd mean I'd be rejected completely for it. If I was rejected for a person who had more experience, then fair enough. But the recruiter told me they didn't select me because of my "lack of technical knowledge". I was borderline stunned. It was unbelievable, which is a pity really because I loved the job description for this position and had this very high on my priority list despite having gone through few other interviews as well. Too bad I couldn't get further in the interview process at this company because I really loved this position.