Testing helps to get instant feedback during your application development. But how do we validate the software when it is working in production? How do we prevent an overload of technical metrics while losing sight of real end-user experience? In this talk we will be touching topics like functional monitoring and synthetic testing. You will learn what these concepts mean and how they fit in with more traditional forms of testing. We will explore how shift left and shift right can work together. There is also an optional hands-on part where you can get your hands dirty and gain some real life how to effectively apply functional monitoring with Datadog and Cypress