DevOps pipeline works as an automated workflow that moves code from development to production through several integrated stages. When developers commit code to a version control system such as Git, the pipeline automatically triggers the build stage, where the application is compiled and dependencies are prepared. Next, the testing stage runs automated unit, integration, and security tests to detect issues early and ensure code quality. If the code passes these checks, it moves to the release and deployment stages, where CI/CD tools automatically deploy the application to staging or production environments using scripts or Infrastructure as Code. Finally, the monitoring and feedback stage tracks application performance and system health to identify issues and improve future releases. Among these stages, automated testing, continuous integration, and monitoring are the most critical for ensuring software quality and reliability because they catch errors early, maintain consistent deployments, and provide continuous insights into system performance.