1. A computer-implemented method comprising: generating, by a computer system, a plurality of articles, wherein each of the plurality of articles includes one or more content items, wherein generating each article in the plurality of articles includes ranking a plurality of content items on a topic, selecting a subset of content items from the plurality of content items based on the respective ranking of each content item, and including the subset of content items in the article, and wherein selecting the subset of content items includes selecting a first content item in a first format and a second content item in a second format, the first content item having the highest ranking of any of the plurality of content items in the first format, and the second content item having the highest ranking of any of the plurality of content items in the second format; generating, by the computer system, a content digest that includes the plurality of articles; transmitting, to a computing device of a user, a notification indicating the content digest is ready to be downloaded; receiving, from the user's computing device, a first request for a first portion of the content digest; in response to the first request and to a determination that a quality level of a connection between the computer system and the user's computing device meets or exceeds a first predetermined threshold, transmitting the first portion of the content digest to the user's computing device at a first time, the first portion comprising lead images from the content digest; receiving, from the user's computing device, a second request for a second portion of the content digest; in response to the second request and to a determination that the quality level of the connection is beneath a second predetermined threshold, transmitting the second portion of the content digest to the user's computing device at a second time, the second portion comprising thumbnails of gallery images, wherein the first and second portions of the content digest are transmitted to the user's computing device without providing any notification of the transmissions to the user.