In the agile DevOps methodology, shift left and shift right are pivotal testing concepts that enhance software development and delivery. Shift left involves incorporating testing and quality assurance early in the development cycle, allowing teams to detect and fix bugs sooner, which reduces costs and accelerates time to market. It emphasizes collaboration, early bug detection, and improved customer satisfaction by ensuring software meets user requirements from the outset. Conversely, shift right extends testing into the production environment, focusing on real-world conditions to ensure software reliability and performance. It provides insights through realistic user testing, continuous feedback, and enhanced monitoring, helping teams address issues that may not appear in earlier stages. Both approaches are crucial in microservices architecture, allowing for comprehensive testing and feedback loops that improve software quality. Organizations benefit from using both strategies to achieve continuous integration and delivery, supported by automated full-stack observability and monitoring. This combination not only enhances agility and efficiency but also ensures robust application security and improved user experiences.