Google App Engine (GAE) is a popular PaaS offering. While its scalable and reliable environment is hidden behind custom API, this makes GAE apps hard to port over to other non-GAE environments. What if one could implement such similar environment? And you could simply move your GAE application’s .war file to this new environment and it would just work? But the question we need to ask ourselves first, how do we know that such alternative environment works in the first place? Java EE has had its Technology Compatibility Kit (TCK) from day one. This time we’ll introduce you to GAE TCK and show you how to run it against an alternative JBoss CapeDwarf GAE API implementation. The GAE TCK is built completely on open source software, and it is a collaboration between Red Hat and Google on making the GAE API and its implementations better. The goal is not just to run the tests, but also engage users and developers with a bunch of exciting extensions that range from cool html reporting to bytecode manipulation of external tests. If you care about GAE, testing, Arquillian, ShrinkWrap, this is the session not to miss!