Facebook's curating is mostly automated. You don't get on your news feed things in chronological order, and you don't get all today's updates on it. Here is a very, very, very long article about how Facebook's news feed works (http://www.slate.com/articles/technology/cover_story/2016/01/how_facebook_s_news_feed_algorithm_works.html). It really doesn't answer how exactly, but it probably gives you some ideas what the Facebook engineers are working on, and how they think, and how they test their product.