You can use AWS Organizations to group accounts into Organizational Units (OUs) based on workload type, environment, or compliance needs. Apply Service Control Policies (SCPs) at the OU level to enforce governance. Use AWS Control Tower or custom landing zones to set up guardrails, logging, centralized billing, and account vending. This isolates workloads, limits blast radius, and provides a scalable foundation for growth.

Start by refactoring the application into smaller services. Use Amazon ECS, EKS, or AWS Lambda for deployment of microservices. Introduce Amazon API Gateway for routing requests, and Amazon SQS/SNS or Amazon EventBridge for decoupled communication. Apply the Strangler Fig pattern—incrementally replace monolith features with microservices—so you can migrate with minimal downtime.

Use AWS Direct Connect to establish a dedicated, high-bandwidth, low-latency connection between the data center and AWS. For redundancy, pair Direct Connect with a VPN connection (backup path). Use Transit Gateway or Direct Connect Gateway to simplify routing across multiple VPCs and Regions. Secure traffic using IPSec, enforce routing policies, and integrate with existing on-premises firewalls.

• Use content delivery (Amazon CloudFront) to reduce origin load and data transfer costs.
• Optimize compute with Auto Scaling, Spot Instances, and Graviton-based EC2 types.
• Choose the right storage tiers (S3 Intelligent-Tiering, EBS GP3, EFS IA).
• Use reserved capacity for predictable workloads.
• Centralize logs and analytics to reduce duplicate storage.
• Design for multi-Region caching to minimize cross-Region transfer costs.

AWS Control Tower provides a preconfigured landing zone with best-practice account structure, OUs, and guardrails. It automates:

• Account provisioning with baseline configurations
• Centralized logging and auditing
• Security controls and SCPs
• Continuous compliance monitoring

This enables consistent governance across accounts without building custom automation.

• Use Aurora Global Database or DynamoDB Global Tables for cross-Region replication.
• Store assets in S3 with Cross-Region Replication.
For routing:
• Use Amazon Route 53 with health checks and failover or latency-based routing.
• Automate recovery using CloudFormation StackSets or Elastic Disaster Recovery to bring up infrastructure in the secondary Region.

• Use multi-AZ or multi-Region database architectures (Aurora, RDS, DynamoDB).
• Apply quorum-based writes or transactional APIs where consistency matters.
• Use write sharding or leader-follower replication carefully to avoid conflicts.
• Balance consistency and latency: choose services like Aurora with Global Database for low-latency reads with consistent failover, or DynamoDB’s strongly consistent read option when required.

• Latency-based routing: When you want to direct users to the Region that provides the lowest network latency, improving performance.
• Geolocation routing: When you need to serve content or comply with regulations based on the user’s location (for example, showing different legal disclaimers or pricing based on country).

The Well-Architected Framework provides structured questions and best practices across six pillars. The trade-off analysis process helps you:

• Evaluate where to prioritize cost, performance, or operational complexity.
• Justify when to choose managed vs. self-managed services.
• Understand risks of availability, security, or compliance gaps.
• Document decisions so architecture evolves in a controlled, auditable way.