Regarding your interview experience, let me comment on some of the points you made, as I've been through a very similar process very recently with Google. They contacted you for a position in the US, and not when you applied to Google Brasil, because there are many many more teams and projects running in the US office, to which your skills might be desirable. They did a GOOD thing. Regarding the pattern you describe of more experienced people being turned down, I can't be sure, but I suspect that, like I realized has happened to me, the type of questions they ask during the interviews are, unfortunately, things that one does not use much during our work years, and get forgotten. So, unless you thoroughly prepare, and review that base CS knowledge, you'll fail the interviews. Something that might not happen with a recent grad, that still has that "academic" knowledge fresh in their minds. Just my 2 cents.