When we shipped #NewTwitter in September 2010, we built it around a web application architecture that pushed all of the UI rendering and logic to JavaScript running on our users’ browsers and consumed the Twitter REST API directly, in a similar way to our mobile clients. That architecture broke new ground by offering a number of advantages over a more traditional approach, but it lacked support for various optimizations available only on the server.
To improve the twitter.com experience for everyone, we've been working to take back control of our front-end performance by moving the rendering to the server. This has allowed us to drop our initial page load times to 1/5th of what they were previously and reduce differences in performance across browsers.
