The presentation will center on automated functional testing in the Java world, with a particular focus on smoke testing, and how to prevent catastrophic failures from reaching the production environment. We will show you how we, at CERN, have leveraged Geb -- a Groovy-based browser automation tool built on top of Selenium -- to develop a full suite of smoke tests for CERN's Electronic Document Handling (EDH) system -- a large web application with over 1 million lines of Java code, in production since 1998, which is used to automate as many as 65 administrative processes across all of CERN's key business areas such as safety, procurement, finance, customs, and training. Though the tool is aimed for use on the JVM, the concepts that will be presented can be applied in other languages that have wrappers for Selenium. In particular, patterns that can be used to better describe and structure functional/smoke tests, as well as how to integrate these tests with continuous integration systems, such as Atlassian Bamboo, using headless browsers (e.g. PhantomJS) or virtual frame buffers.