A company runs a monolithic on-premises application that is hard to scale and maintain. They plan to migrate it to AWS and split it into microservices. Which AWS Well-Architected best practice does this plan follow?

Implementing loosely coupled dependencies is a core tenet of the Operational Excellence pillar of the AWS Well-Architected Framework, specifically within the design principles for evolving applications. By breaking a monolithic application into microservices, the company is reducing interdependencies between components. This makes individual services easier to develop, deploy, scale, and maintain independently, improving agility and resilience. The other options are also good practices but don't directly address the architectural shift from monolithic to microservices for improved scalability and maintainability: "Integrate functional testing as part of AWS deployment" is a good practice for reliability and operational excellence but doesn't define the architectural pattern itself. "Use automation to deploy changes" is a best practice for operational excellence and speed, applicable to any architecture. "Deploy the application to multiple locations" (e.g., multiple Availability Zones or Regions) is a best practice for reliability and high availability, independent of the microservices architecture.