The business-critical nature of digital payment systems demands extensive end-to-end testing, as these systems often integrate many different actors. As the number of test cases multiplies, testing becomes increasingly time-consuming and costly to carry out. This thesis presents an automated testing framework to support the execution of highly parameterized end-to-end test flows. The solution integrates multiple technologies: based on the Java platform, it employs Selenium WebDriver for browser automation, JUnit as the test engine and reporting infrastructure, and a custom Domain-Specific Language implemented in Groovy that serves as a builder for a predefined set of test cases. The DSL allows users to easily configure the parameters of each test scenario, from payment card details to target environment settings.