Karpenter is an open-source Kubernetes node autoscaler developed by AWS. It automatically launches the right compute resources (EC2 instances) when your cluster needs them and shuts them down when they’re no longer needed.

Traditional autoscalers (like the Cluster Autoscaler) work well but can be slow and limited in flexibility. Karpenter is designed to be:

Faster: It reacts quickly to unschedulable pods. Smarter: It chooses the best instance types based on your workload needs. Cost-efficient: It can use spot instances and right-size nodes to save money. Flexible: It doesn’t require pre-defined node groups.