receiving, from a client device, a search query for searching a hybrid search index;

in response to the search query, generating, from the hybrid search index, a search result comprising one or more content items corresponding to the search query;

ranking the one or more content items within the search result according to observation layer data defining historical display locations of the one or more content items included in the search result, world state data defining device metrics and environmental metrics of the one or more content items, and user interaction data corresponding to the one or more content items; and

based on ranking the one or more content items, providing the search result for display on the client device in ranked order within a search result interface.