MongoDB is a popular document database used for a wide variety of applications. In this session we will look at using MongoDB for representing graphs.

In the first part of this talk we will look in detail at a reference implementation of an open source social platform backend called "Socialite" and how graph relationships can be modeled in MongoDB.

In the second part of the talk we will look at a new aggregation operation that we recently implemented for graph traversal and computing transitive closure. We will include an overview of the implementation details, including some of the challenges we faced and design decisions we made along the way.