Google Developer interview questions

First of all you need to have a reference in Google wihout reference you are not even in for first round

I have got very positive impression of how Google manages interviews. A friend of mine made a recommendation and the process started after about two weeks. We scheduled the phone screen after four weeks. The interview containes 3 programming questions and last 45 minutes. Some answers were not crystally right. After the interview I had an opportunity to ask about the company. I have got an impression that I advanced into the next level, but it was wrong. The hiring manager adviced me to take part in open source projects.