1. A method comprising: determining counts of one or more user interactions with one or more content items created by an author, each user interaction of the one or more user interactions having an associated time; classifying, based on respective associated times of the user interactions, the determined counts of the user interactions with the content items into predetermined time intervals spanning a first duration; computing an engagement model for the author comprising a plurality of engagement values corresponding to the predetermined time intervals, wherein the plurality of engagement values are computed by dividing the classified counts corresponding to the predetermined time intervals by a number of the content items created by the author; determining, at a particular time in the first duration, an actual number of interactions with a particular content item created by the author; estimating, at the particular time for a second duration, an estimated number of interactions with the particular content item created by the author based on a summation of the plurality of engagement values of the engagement model and the determined actual number of interactions with the particular content item; computing a popularity score for the particular content item based on the estimated number of interactions; determining a display location of the particular content item in a displayed content stream based on the popularity score; and providing the particular content item for display in the displayed content stream based on the determined display location.