You can write unit- and integration tests in different ways, though sometimes you need to write higher level tests, such as end-to-end tests, which are often hard to write. This talk will show you examples of how to write end-to-end tests by using JUnit Jupiter Extension mechanism with the support of Testcontainers and, as a foundation, Spring Boot, in a convenient way. By using frameworks like Spring Boot, there is already very good support within the framework to write tests and integration tests but if you have to deploy not on the Cloud (like DC/OS, K8S etc.), you might have issues to create an appropriate test environment. In particular, if you have several participants needed to get your application correctly running. So, based on JUnit Jupiter, Testcontainers, and some Java code, you can write real end-to-end Tests which are very helpful in several ways. It makes it more or less easy to create end-to-end Tests which can be run via your IDE also. There are several aspect which need to be taken care of, like how to synchronise the application and your test code, and so on.