Well there is certainly "actual work" done in overseas Google offices... ;-) Sometimes many groups from different places work together on a larger project. E.g

Well there is certainly "actual work" done in overseas Google offices... ;-) Sometimes many groups from different places work together on a larger project. E.g. there are teams working on "search engine algorithms" in many different countries. Or sometimes you have a smaller project that is just handled in one office. Like the javascript engine for Chrome was done out of Denmark I believe. I'm not sure about other big companies but Google at least doesn't interview on a group-by-group basis. So during the interview itself, they wouldn't know yet what group you would be working in. That discussion comes later.