The interview was mostly a behaviorial. They just wanted to see if I had any experience in the work they were doing - performance profiling. The team was extremely friendly and asked me a lot about my projects and my previous work ex. Unfortunately, they were looking for someone with a stronger Python skills and more experience with performance optimization than what I had had, and therefore didn't get the offer. They relayed the message to through a phone call, which was rather surprising since most rejections are done through mail. However, the entire experience was extremely smooth.