I was interviewed upon a friend's recommendation, so that was a leg up. Exchanged email with the owner of the company, got a date for on-site interview, went to Alewife station (that's where the company building is). I got lost and wasted a lot of energy trying to get to the company building, so I was already tired by the time I was there. Mixed with the lack of preparation for whiteboard questions (which I did not expect to get because my friends apparently didn't get one at his interview), I did pretty badly.