Cluster Autoscaler (CA) is a widely adopted solution for Kubernetes cluster autoscaling that operates at the node group level, leveraging cloud providers' abstractions to scale predefined node groups based on pending pods. It offers cost and resource optimization benefits but may lead to inefficiencies due to its reliance on predefined node groups and limited flexibility in general. On the other hand, Karpenter is a more flexible solution that dynamically provisions nodes with custom instance types, optimizing for cost and performance, and supporting faster scale-up times. Its simplified operations approach makes it an excellent fit for dynamic workloads and cost-sensitive operations, but its primary support for AWS environments may limit its applicability in multicloud scenarios.