GNN Applied to Ego-nets for Friend Suggestions
This work addresses the challenge of scalable friend suggestions for social network users, representing an incremental improvement over existing methods.
The paper tackles the problem of making friend suggestions in large social graphs by introducing a framework that reduces link prediction to low-scale tasks on ego-nets, enabling the use of complex supervised models without sacrificing scalability. The proposed WalkGNN model outperforms baseline methods in offline experiments on the Ego-VK dataset and shows growth in business metrics in live A/B tests.
A major problem of making friend suggestions in social networks is the large size of social graphs, which can have hundreds of millions of people and tens of billions of connections. Classic methods based on heuristics or factorizations are often used to address the difficulties of scaling more complex models. However, the unsupervised nature of these methods can lead to suboptimal results. In this work, we introduce the Generalized Ego-network Friendship Score framework, which makes it possible to use complex supervised models without sacrificing scalability. The main principle of the framework is to reduce the problem of link prediction on a full graph to a series of low-scale tasks on ego-nets with subsequent aggregation of their results. Here, the underlying model takes an ego-net as input and produces a pairwise relevance matrix for its nodes. In addition, we develop the WalkGNN model which is capable of working effectively in the social network domain, where these graph-level link prediction tasks are heterogeneous, dynamic and featureless. To measure the accuracy of this model, we introduce the Ego-VK dataset that serves as an exact representation of the real-world problem that we are addressing. Offline experiments on the dataset show that our model outperforms all baseline methods, and a live A/B test demonstrates the growth of business metrics as a result of utilizing our approach.