Test automation (TA) activity has become a key critical work to guarantee the quality of system under test (SUT) by driving test and also development effort effectively. To bring this efficiency to projects, companies are investing on TA projects in a more motivated way. The question here is how we should design the automation strategy to handle complex TA projects together effectively. It can be done by automating test scenarios as E2E (end to end). Vertical E2E TA consists of; automating Test Data Preparation Phase and Unit, Integration and UI tests. For horizontal E2E TA; UI and Integration test cases, which are automated, designed as integrated real user scenarios. I will tell about the prerequisites, principles and key factors to have E2E automated tests. And also I will share hands on experienced E2E test automation projects that Selenium was the key tool.