Managed Kubernetes services, like Amazon's EKS, simplify cluster management but require additional steps for app lifecycle management. Using Pulumi for Day 2 Kubernetes administration, this guide demonstrates setting up an EKS cluster with node groups and migrating workloads without downtime. Initially, an EKS cluster with two node groups is created to host applications like EchoServer and NGINX Ingress Controller. The process involves defining infrastructure dependencies with Crosswalk for AWS and deploying workloads using Pulumi. The guide then explores migrating NGINX to a new node group with an updated configuration, ensuring continuous operation during the transition. Pulumi's code-driven approach facilitates the management of Kubernetes infrastructure, offering benefits such as simplified resource management and adherence to best practices. The document emphasizes conducting load tests to ensure no requests are lost during the migration and provides steps for decommissioning unused node groups, highlighting Pulumi's utility for infrastructure management and application deployment in Kubernetes environments.