Comment by shereadsthenews

That is taken out of context. Practically all Google server code is written in C++ or, at a much smaller scale, Java. Go is used for logs analysis, internal services, monitoring and automation, etc. Nobody at Google reaches for Go when they are thinking of high performance nor would anyone try to optimize a large service in Go. They would just write it in C++ instead as soon as it starts to cost non-trivial amounts of money. Remember that Pike wrote Sawzall and Go replaces it, in a similar role.