Systems, methods, and machine-readable media for monitoring the locations of a number of entities are provided. The system may be configured to track the locations of a multitude of entities by grouping entities together into clusters of entities based on their geographic proximity and trajectories. A member of a cluster may be identified as a leader or a follower. The system may receive a number of location reports for the entities and update the locations of the entities based on whether the entity is a leader or a follower. For example, the system may update a back-end location database with the location information for a leader while location updates for followers may be converted into locations that are relative to the corresponding leader's and cached at the system.