The initial Core BTS interview was mostly informal hosted at an informal restaurant, but all parties were well dressed and professional. It was very stress free and we just had a conversation. If you are confident of your skills then you will do fine. The next step was the formal interview hosted at the employers location. This was mostly a conversation with random parties talking to each other and throwing questions at me. I felt very relaxed and confident. A week later I was re-asked my salary requirements and processed by HR.