Here at The New York Times we are using it to power some of our recommendation algorithms. We are actually training the models with Python and serving them with Go using gonum.
Our library was just open sourced (and still in my personal account, until we add more documentation): https://github.com/jbochi/facts
Our library was just open sourced (and still in my personal account, until we add more documentation): https://github.com/jbochi/facts