I’ve got the interview through referral scheme by my friend. The first stage was with a recruiter to discuss about my experience and why I decided to leave the current etc. The same day I got a message saying they are proceeding with application and to select some time slots. The next level was with a staff and senior engineer. They talk about my ambitions and my previous experiences. On the last part we can choose either a code review or a whiteboard exercise. I chose the whiteboard and asked to solve a possible problem the architecture might face. I completely misunderstood the question and talked in cloud format but they were expecting a design pattern solution. Unfortunately, on the same day they came up with feedback which was negative. But the feedback was constructive and personalised than a generic reply mail.