The performance of a web application is the most crucial non-functional aspect that is often ignored and not tested. Their implications are difficult to understand, hard to predict and in most cases connected with bad user experience and revenue loss. With Lighthouse, WebPageTest and other tools you are already able to capture tons of performance metrics of your application. However understanding and testing them often feels difficult and painful. In this talk, Christian will present you the most important performance metrics and ways how you can easily set up performance tests using WebDriver as part of your CI/CD pipeline.