Facebook is one of the most feature-rich apps available for Android. With features like push notifications, news feed, and an embedded version of Facebook Messe

Facebook is one of the most feature-rich apps available for Android. With features like push notifications, news feed, and an embedded version of Facebook Messenger (a complete app in its own right) all working together in real-time, the complexity and volume of code creates technical challenges that few, if any, other Android developers face I've never understood why the Facebook client is so heavy. That isn't a long list of features! It seems like the requirements could be written on the back of an envelope. Obviously part of the reason is that they move fast and have a lot of developers, so there's much more pressure to add code than to keep it trimmed down. But the client still doesn't do all that much. Surely, surely most of the logic is handled on the server.