Testing in Continuous Delivery involves shifting tools and knowledge to earlier phases of the engineering process, known as shift left, to ensure quality and prevent defects. This approach requires collaboration between developers, testers, and operations teams to create a strategy for the whole process, including simple testing notes during specification and automated tests throughout development. In testing, automation is key, with a focus on quick and stable quality feedback, while also leaving room for manual tests that are crucial from a business perspective. Operations phase involves collecting end-user feedback through application logs and metrics, and using techniques like canary releases to test features in production environments. The continuous delivery methodology has led to the emergence of DevOps, TestOps, and other related practices, which involve combining quality efforts across development and production environments.