This document describes Cerberus, an open source test automation tool developed by La Redoute. Cerberus allows centralized management of test cases across multiple technologies like web, mobile, and APIs. It supports features like a step library, test automation, execution reporting, and integration with other tools. The document also provides examples of how Cerberus is used at La Redoute for regression testing websites in multiple languages and environments. It maintains over 3,500 regression tests that execute twice daily. Cerberus can also be used for functional monitoring of websites by regularly executing test cases and monitoring performance metrics.