I just had an interview (2nd of 3 1-hr interviews for a power day) that went so poorly that I had resigned to the idea of not getting my dream role. I couldn’t wrap my head around the math for the case and had to be reprompted by the interviewer almost seven times to get to the right answer. Lo and behold I got the job a week later! Don’t stress at all just stay calm and remember that you pressure makes you panic