TL;DR — LinkedIn News Feed

Design the LinkedIn news feed — a professionally-focused content ranking system that surfaces relevant posts, articles, and job-related content to 300M monthly active users. Unlike Twitter's chronological model, LinkedIn's feed is heavily ranked: a post from a 2nd-degree connection can appear above a direct connection's post if the ranking model predicts higher engagement. Key features: Show ranked feed of posts from connections and followed entities. Support post types: text, image, video, article, poll, document.