1. A method for a server computer system comprising: identifying, by a processing device in a content sharing platform, a bucket comprising a plurality of content items associated with a group of users of the content sharing platform that have similar interests; associating a bucketing token pertaining to the bucket with each of the plurality of content items, the bucketing token comprising a unique identifier that identifies the plurality of content items as being associated with the group of users of the content sharing platform that have similar interests; receiving a request for the bucketing token from a ranking service; and providing the bucketing token to the ranking service, the ranking service to use the bucketing token to determine, with respect to a first user of a social network platform, a ranking score for a content item of the plurality of associated content items in view of one or more interests of the first user of the social network platform that is separate from the content sharing platform.