1. Just explained why I was passionate. Seemed more like a superficial question and they did not care about the answer. 2. I couldn't figure out the answer because it was so general. I realized I should have presented a specific problem, so I failed to answer and just said how I solved most problems that came to me with unit testing, looking up from documentation , tech forums, etc. 3. I did not know the answer at the time and I felt the interview soured after that. Very sad, because it is a simple concept I looked up and felt that the demand for reference lvel knowledge of every .Net API is the worst way to assess a developers understanding of it. 4. I felt stupid for missing this one.. But it was another reason I flunked. Some reason I mixed up Performance Tuning as being a specific SQL feature to just writing optimized queries that do not result in more