I was told the interview would be about a topic that was not covered during the actual interview. More like I was trolled. I pair programmed with two different developers working with the actual codebase during the interview. We basically wrote unit tests for 4.5 hours. It was not that enjoyable because I was not given any time to familiarize myself with the codebase. It was a "jump right in" type situation. I am not sure how I could have performed better given extreme unfamiliarity with their codebase. I hope you have better luck than me. I spent the entire day there which was way too long considering I was not paid for it. The recruiter did not give me much information about the interview schedule until I asked on multiple difference occasions.