Web 2.0 moves much of the application functionality directly into the browser. While creating a richer user-experience that everyone craves, these technologies pose significant new challenges for testing. Matt Brayley-Berger discusses areas that are critical in testing Web 2.0 applications. First, Matt presents an overview of a typical Web 2.0 application architecture (tiers, backend databases, and application workflow) to help you plan test designs and test cases. He explains how to architect testing directly into the application, including instrumenting the application to provide data for use by testing tools. Learn why testers must focus more on performance testing that accurately profiles the asynchronous inter-application communication. Take back ways to correlate low-level metrics (EJBs, Flex/Flash Remoting, business logic layer) with browser-specific execution times to obtain a more accurate representation of the response under various states of load.