I have been contacted for a on-site interview and have been very suprised by the lack of knowledge of some of them developers. A interviewer ask me a question in SQL and was unable to understand a JOIN. I have synchronized a Singelton and the inerviewer was unable to confirm me it was race-condition free. The last interviewer didn't ask me single question in Java , 5 hours for nothing for finally tell me that they looking for someone with more knowledge.