Thanks to frameworks like Phoenix, web services can be developed quickly. The result is scalable, fast and easy to adapt. A perfect platform to create really complex web services. When software gets more complex, it gets harder to test. There are many different parameters one can supply, posted JSON data types can have different dependencies and the order in which things happen may play a role. Thus, even if Phoenix helps a lot in getting a correct and complex web service produced, there still are possibilities for mistakes. These mistakes have to be found and testing is a way to do so. QuickCheck helps to automatically generate test cases for such web services.