This document discusses Yahoo's use of isomorphic React and Flux to build web applications. It begins with background on the presenter and an overview of isomorphic web applications. The document then covers React, Flux, and building an isomorphic version by running Flux on the server. Key challenges discussed are handling server-only libraries, including CSS for dynamic modules, and transferring state between server and client. Links are provided to examples of Yahoo's implementation and approaches to CSS. The presentation concludes with time for questions.