Ask HN: Are there any examples of big node.js installs?

I am investigating using node.js for some large upcoming projects. It is obviously vertically scalable. And I know you can use multi-node for single machine muti-core utilization and of course we have our load balancers for the front end. At a proof of concept level, it has proven itself. However, I need a case study or two to show the upper management that it is in fact all-around capable of being a rock solid production environment that can service millions of users. Does anyone know of any such proof that is publicly available?