Wasn't at a huge scale but for one project another intern and I took a proof of concept that another engineer had done with Gremlin [1] and turned it into a full tool and ended up using dgraph. The python bindings were easy to work with and Ratel (the UI/web frontend) made quick searches and tests easy.
I liked working with it so now I'm the package maintainer for it on AUR [2]. At some point I'd like to make a repo showing how to implement common graph algorithms with the python bindings, since GraphQL+- currently only supports k-shortest path at the query level [3].
I think the latest release is 20.03.1, perhaps time to update?