Abstract: Systems and methods of the present disclosure enable secure data aggregation in an aggregation database. The aggregation database has an aggregation database schema configured to communicate with entity-specific databases via entity-specific secure connections. The aggregation database receives, from the entity-specific databases, user profiles having an entity identifier identifying an entity, and a metric associated with a user. Groups associated with the user profiles are determined based on the metric associated with each user profile. The user profiles are ranked within each group for a ranking across the entity-specific databases based on the metric. A percentile rank in each group across the entity-specific databases is determined for each user profile. Each user profile is modified to include the percentile rank and are returned to each entity-specific database without other user profiles not associated with each respective entity-specific database.