End-to-End Testing is a testing method that tests the workflow of an application from beginning to end along with its integrations with external systems. It is essential for verifying the functionality of the entire system workflow while gaining more confidence by detecting bugs and increasing the test coverage to sub-systems. End-to-End Testing aims to validate the complete application for data integrity, dependencies, and communication with other interfaces, systems, and databases to cover a full production scenario. This is not easy, and there comes TestUp for rescue. It automates all the main user flows in a staging environment and tests them regularly to ensure that the whole system performs well.