AWS re:Invent 2025 - From monolith to microservices: Migrate and modernize with Amazon EKS (CNS210)

From Monolith to Microservices: Migrate and Modernize with Amazon EKS

Migrating from Monolithic to Microservices Architecture

• Monolithic applications have benefits like simplicity and lower operational complexity, but struggle to keep up with evolving business needs
• Microservices architecture promises more agility, flexibility, and faster innovation by breaking down applications into independent, loosely coupled services
• Key advantages of microservices:
  • Functional isolation and independent scaling of services
  • Autonomous development teams with flexibility in technologies
  • Alignment of team structure to service ownership
  • Compatibility with elastic cloud infrastructure

Transitioning the Monolith with the Strangler Fig Pattern

• The strangler fig pattern allows gradually migrating a monolith to microservices at a controlled pace
• Identify services to break out first, leave the rest of the monolith intact initially
• Incrementally migrate more services over time as the microservices architecture matures

Containerizing Microservices with Docker and Kubernetes

• Containers provide a consistent environment from development to production
• Kubernetes orchestrates and manages containers at scale, providing service discovery, load balancing, auto-scaling, and more
• Managing open-source Kubernetes can be complex, requiring undifferentiated heavy lifting

Introducing Amazon EKS for Managed Kubernetes

• Amazon EKS is a managed Kubernetes service that handles the Kubernetes control plane and cluster management
• Key benefits of EKS:
  • Accelerates innovation by offloading Kubernetes management
  • Optimizes cost and performance with native AWS integration
  • Enhances availability, scalability, and reliability with AWS best practices
  • Runs Kubernetes workloads in any environment, including on-premises with hybrid nodes

Addressing Multi-Tenant Isolation and Operations Challenges

• As the microservices architecture scales, managing multiple clusters for individual customers becomes operationally complex
• Key requirements for a multi-tenant architecture:
  • Namespace-based isolation to reduce cluster count
  • Network policies to create secure "digital fences" between tenants
  • Resource quotas and limit ranges to prevent noisy neighbor issues
  • Automated provisioning and management of underlying infrastructure

Leveraging AWS Services and Infrastructure as Code

• Use AWS Controllers for Kubernetes (ACK) to declaratively provision AWS resources like S3, RDS, and SageMaker
• Integrate with GitOps workflows using tools like Argo to automate infrastructure provisioning
• Extend the Kubernetes control plane to manage the entire application and infrastructure lifecycle

Key Takeaways

• Microservices architecture enables more agile, flexible, and innovative application development
• EKS simplifies Kubernetes management and operations, accelerating the migration to microservices
• Multi-tenant isolation, resource management, and infrastructure automation are critical for scaling microservices
• Integrating AWS services and infrastructure as code streamlines the entire application lifecycle

Technical Details

• Kubernetes features utilized: namespaces, network policies, resource quotas, limit ranges
• AWS services mentioned: EKS, EKS Auto Mode, EKS Hybrid Nodes, AWS Controllers for Kubernetes (ACK), SageMaker, Bedrock
• GitOps tools: Argo CD
• Operational tools: Kube-bench, Open Policy Agent (OPA), Kyvern

Business Impact

• Enables faster time-to-market and more responsive innovation to meet evolving customer needs
• Improves operational efficiency by automating infrastructure provisioning and management
• Enhances security and compliance through centralized policy enforcement and auditing
• Optimizes resource utilization and cost by dynamically scaling infrastructure based on demand

Use Cases

• ISV with a successful monolithic application transitioning to microservices
• SaaS provider scaling their multi-tenant architecture on AWS
• Enterprise modernizing legacy applications with microservices and cloud-native technologies