The biggest pain as a developer in a big development team, building a system consisting of tens of services over Microservices architecture, is pushing code to the code base without breaking anything. Testing is the key for solving this pain. Or, in other words, establishing an healthy CI-CD process that surfaces defects before they get to the client. In this talk we’ll explore different approaches of testing that will help us deliver code that works and doesn’t break older functionality. We will talk about different approaches of testing in the service level – Unit testing vs Api testing. We will talk about the importance of Integration testing and also about what we can do in order to minimise the risk of deploying new piece of code through Blue-Green deployment and Canary release.