Bridging the Semantic-Collaborative Gap: An Asymmetric Graph Architecture for Cold-Start Item Recommendation
This work addresses the cold-start problem for both new content and new devices in recommender systems by formulating it as an inductive graph completion task on a temporal bipartite device–content graph. The authors propose an asymmetric graph architecture: the device tower captures collaborative signals through message passing over viewing histories, while the content tower generates embeddings solely from intrinsic semantic features, without relying on item IDs or interaction data. A Shallow-RHS design maps content semantics into a collaborative-aware embedding space. The approach is further extended to device cold-start by leveraging demographic features to construct cohort embeddings for implicit graph completion. Integrated with approximate nearest neighbor retrieval, the system enables real-time embedding generation and candidate recall. Large-scale online experiments demonstrate significant improvements in user engagement, content exposure, ramp-up speed for new content, and key metrics for new devices.