Explain how you have implemented automated testing and what tools you have used for unit testing, integration testing, and end-to-end testing.

Automated testing was a crucial part of our CI/CD pipeline. For unit testing, we used frameworks specific to the programming languages such as JUnit for Java and pytest for Python. Integration tests were automated using tools like Postman and Newman, ensuring seamless communication between microservices. End-to-end testing was performed using tools like Selenium for web applications, guaranteeing that the entire system functioned correctly from the user's perspective. Automated tests were executed with every code commit, ensuring code quality and reliability before deployment.