Most Google projects are not written in GWT for the frontend, they are written in Javascript using Closure and the Closure compiler, that includes Gmail, Search

Most Google projects are not written in GWT for the frontend, they are written in Javascript using Closure and the Closure compiler, that includes Gmail, Search, G+, Docs, Drive, etc. Really, it sounds like this guy got put onto a team project he didn't like, but Google has very large codebases in C/C++, as well as JS, and there is ample opportunity to work on non-Java stuff. Chrome and Android (non-userland) in particular. Any company with a team of people is going to have to place limits on polyglotism and have standards for readability and coding. I like Scala too, but the idea that a company is going to allow anyone to just pick any PLT research languages that they personally like sounds far-fetched.