The Container Orchestration Decision
When running containers on AWS, you have two primary managed options: Amazon EKS (Elastic Kubernetes Service) and Amazon ECS (Elastic Container Service). Both are production-ready, battle-tested services used for Kubernetes and container orchestration—but they serve different needs and come with different trade-offs.
As AWS DevOps consultants who've implemented both services across 100+ projects, we've seen organizations succeed (and struggle) with each. This guide shares what we've learned to help you make the right choice.
Quick Comparison
| Aspect | Amazon EKS | Amazon ECS |
|---|---|---|
| Technology | Managed Kubernetes | AWS-proprietary orchestrator |
| Control Plane Cost | $0.10/hr (~$73/month) | Free |
| Learning Curve | Steep (Kubernetes) | Moderate (AWS-native) |
| Portability | High (K8s anywhere) | AWS-only |
| Ecosystem | Massive (CNCF) | AWS ecosystem |
| Fargate Support | Yes | Yes |
| EC2 Support | Yes (managed node groups) | Yes (capacity providers) |
| Service Mesh | Istio, Linkerd, App Mesh | App Mesh |
| GitOps Tools | ArgoCD, Flux, native | Limited options |
| Best For | Complex, portable workloads | AWS-native, simpler ops |
When to Choose Each Service
Compare side-by-side to find the right container orchestration for your team.
Choose EKS
Kubernetes flexibility & portability
Same K8s manifests work on AWS, GCP, Azure, or on-premises with minimal changes.
Leverage existing investment. kubectl, Helm charts, and K8s patterns transfer directly.
Custom controllers, operators, CRDs, service mesh (Istio/Linkerd), full CNCF ecosystem.
Sophisticated deployment patterns, traffic management, and observability at scale.
ArgoCD, Flux have first-class K8s support. Declarative, version-controlled infra.
K8s skills are portable across employers. Easier to hire than ECS-specific knowledge.
Choose ECS
AWS-native simplicity & integration
Deep integration with IAM, CloudWatch, ALB, Secrets Manager. No external deps.
Gentler learning curve. Get containers running in production without K8s investment.
No control plane costs, simpler networking. Great for startups and small teams.
Running a handful of services? ECS handles this elegantly without K8s ceremony.
ECS Anywhere, App Runner, Container Insights, seamless IAM roles for tasks.
Single vendor support. AWS handles everything—no finger-pointing between vendors.
Cost Comparison
Understanding the true cost requires looking beyond control plane pricing.
Control Plane
At scale with multiple clusters, EKS costs add up. But for most organizations, this is a small percentage of total spend.
Compute (EC2/Fargate)
Compute costs are the same for both services. Fargate pricing is identical whether running on EKS or ECS.
Operational Cost
Hidden cost: EKS requires more skilled (expensive) engineers, but those skills are more portable across employers.
Architecture Deep Dive
Understanding the architectural components of each platform.
EKS Architecture
AWS-managed Kubernetes masters (etcd, API server, controllers)
Managed node groups, self-managed nodes, or Fargate
VPC CNI plugin for native VPC networking
CoreDNS for internal DNS resolution
AWS Load Balancer Controller for ALB/NLB
EBS CSI, EFS CSI drivers for persistent volumes
ECS Architecture
AWS-managed ECS service (completely free)
EC2 capacity providers or Fargate serverless
awsvpc mode for task-level ENIs
AWS Cloud Map integration
Native ALB/NLB integration built-in
EFS, EBS volumes via task definitions
Decision Framework
Answer these questions to guide your decision.
Multi-Cloud Plans?
Yes → EKS. Kubernetes manifests and operational knowledge transfer across clouds. No → Either, but ECS is simpler if you're AWS-only.
Team Size & Skills?
Small team, no K8s experience → ECS. Faster path to production. Dedicated platform team or K8s skills → EKS. Leverage existing expertise.
Workload Complexity?
Simple services, basic scaling → ECS. Don't over-engineer. Complex microservices, custom operators, service mesh → EKS. You'll need the flexibility.
Ecosystem Needs?
Need ArgoCD, Istio, custom CRDs → EKS. CNCF ecosystem is unmatched. AWS-native tools sufficient → ECS. Simpler integration.
Long-Term Strategy?
Building platform capabilities → EKS. Investment pays off at scale. Focus on product, not platform → ECS. Let AWS handle orchestration complexity.
Migration Considerations
Moving to Kubernetes
Convert task definitions to K8s manifests. Reconfigure networking (awsvpc → VPC CNI). Update CI/CD pipelines. Plan for learning curve. Typical timeline: 4-8 weeks.
Simplifying Operations
Convert K8s manifests to task definitions. Replace K8s-specific features (CRDs, operators). Update tooling. Less common but valid for reducing complexity. Timeline: 2-4 weeks.
What Transfers
Container images work on both. Core networking concepts similar. Monitoring patterns transfer. IAM concepts apply to both. The application code doesn't change.
