Improving Facebook on Android

What this post added

This post details significant improvements made to the Facebook Android app focusing on performance, data efficiency, networking, and application size. Key contributions include: deferring non-critical initializations to improve startup times, fetching News Feed stories earlier for faster loading on poor networks, optimizing image downloads using WebP compression (25-35% savings over JPG) and adaptive resolution loading based on viewport size, and fine-tuning image caching strategies. The networking stack was enhanced by adopting OkHttp, enabling faster retries and SPDY protocol support, leading to a 90% reduction in slow/failed image loads. Application size was reduced by 65% by utilizing Google Play's ability to upload multiple APKs for different device configurations. Automated tests and instrumentation were developed to monitor and prevent regressions in data usage and app size.