Amazon Web Services (AWS) offers two prominent container orchestration solutions: Amazon ECS (Elastic Container Service) and Amazon EKS (Elastic Kubernetes Service). While both serve the purpose of running containers at scale, they cater to different operational models. As organizations grow and their infrastructure becomes more complex, many begin to evaluate the move from ECS to EKS—seeking greater flexibility, portability, and access to the wider Kubernetes ecosystem.
This blog explores why companies are migrating from ECS to EKS, the benefits and challenges of such a shift, and key considerations to ensure a smooth transition.
Why Move from ECS to EKS?
1. Vendor Neutrality and Portability
ECS is AWS-native and tightly integrated into the AWS ecosystem. While this ensures tight coupling with AWS services, it also limits portability. EKS, being based on upstream Kubernetes, allows organizations to move workloads more easily between cloud providers or even run them on-premises.
2. Standardization
Kubernetes has become the de facto standard for container orchestration across cloud providers. Moving to EKS aligns teams with this industry standard, enabling access to a broader talent pool, more extensive documentation, and a larger ecosystem of tools.
3. Ecosystem and Extensibility
Kubernetes offers richer ecosystem support—such as Helm for packaging, service meshes like Istio, operators, CRDs (Custom Resource Definitions), and robust community-driven integrations. These features enable more sophisticated deployment and operations patterns than ECS typically supports.
4. Advanced Scheduling and Autoscaling
EKS provides greater flexibility in terms of scheduling policies, node affinities, and advanced autoscaling mechanisms (e.g., Karpenter). While ECS has its own scaling tools, they are simpler and often less customizable.
Key Differences Between ECS and EKS
| Feature | Amazon ECS | Amazon EKS |
|---|---|---|
| Orchestration Model | AWS-native | Kubernetes-native |
| Portability | AWS only | Multi-cloud, hybrid support |
| Learning Curve | Lower | Higher |
| Ecosystem | Limited to AWS | Vast, Kubernetes ecosystem |
| Community Support | AWS docs | Global Kubernetes community |
| Customization | Less granular | Highly customizable |
| Cost | Typically lower operational cost | Potentially higher, but more control |
When Is the Right Time to Migrate?
The decision to migrate from ECS to EKS depends on your organizational goals, application complexity, and infrastructure maturity. Here are common signals it might be time:
You want to standardize on Kubernetes across environments.
Your team is building cloud-agnostic services.
You’re hitting limitations in ECS around networking, scheduling, or service discovery.
You're adopting advanced CI/CD tools that integrate better with Kubernetes.
You're consolidating infrastructure for microservices or multi-tenant environments.
Challenges in Migrating from ECS to EKS
While EKS offers significant benefits, migration is not trivial. Key challenges include:
1. Learning Curve
Teams familiar with ECS must invest time in understanding Kubernetes concepts such as pods, deployments, services, namespaces, and volumes.
2. Infrastructure Complexity
EKS introduces a more complex control plane and infrastructure setup. Managing IAM roles, networking (VPC CNI), and persistent volumes requires deeper operational knowledge.
3. Service Redefinition
Applications often need to be reconfigured to fit Kubernetes constructs. ECS task definitions and services do not directly map to Kubernetes YAML manifests.
4. CI/CD and Monitoring Overhaul
CI/CD pipelines, monitoring tools, and observability stacks must be reworked to integrate with Kubernetes tooling (e.g., Prometheus, Grafana, ArgoCD).
Steps to Migrate from ECS to EKS
Here’s a high-level roadmap to help plan the transition:
1. Assess and Plan
Inventory ECS workloads and define migration priorities.
Identify services with high cloud portability needs or requiring Kubernetes-native features.
2. Build Your EKS Cluster
Set up an EKS cluster using tools like
eksctl, Terraform, or the AWS Console.
Choose between managed node groups, Fargate, or a combination depending on workload requirements.
3. Prepare Kubernetes Manifests
Translate ECS task definitions into Kubernetes manifests.
Define deployments, services, ConfigMaps, Secrets, and Ingress resources.
4. Set Up CI/CD and Monitoring
Integrate CI/CD pipelines with tools like GitHub Actions, ArgoCD, or Jenkins.
Deploy observability tools such as Prometheus, CloudWatch Container Insights, or Grafana for monitoring.
5. Test and Validate
Deploy services in a staging environment.
Validate service discovery, autoscaling, logging, and network policies.
6. Migrate Incrementally
Start with non-critical services.
Use blue/green or canary deployments to minimize risk.
Gradually phase out ECS workloads after validation.
Tools That Help With ECS to EKS Migration
While there’s no one-click migration tool, a few resources can streamline the process:
AWS App2Container (A2C): Helps containerize legacy applications and deploy them on EKS.
Helm: Package manager for Kubernetes applications.
eksctl or Terraform: Automates EKS cluster creation.
Karpenter or Cluster Autoscaler: Helps optimize node usage post-migration.
Should You Run ECS and EKS Together?
In some cases, the best solution isn’t a full migration, but a hybrid approach. Running ECS and EKS in parallel can provide:
Gradual transition over time
ECS for simple, low-maintenance workloads
EKS for dynamic, scalable, and customizable applications
However, this increases operational overhead and should be weighed carefully.
Conclusion
Migrating from ECS to EKS represents a significant but strategic move for organizations seeking greater flexibility, control, and alignment with modern cloud-native practices. While the transition involves upfront effort—especially in retooling, retraining, and reconfiguring—EKS unlocks powerful capabilities that enable teams to innovate faster and scale smarter.
If your organization is planning for long-term cloud infrastructure scalability and standardization, embracing Kubernetes via EKS can be a transformative step. Prepare thoughtfully, migrate incrementally, and equip your team with the right tools—and the payoff will be well worth it.