Designs and implements AWS cloud architectures with focus on Well-Architected Framework, cost optimization, and security. Use when: 1. Designing or reviewing AWS infrastructure architecture 2. Migrating workloads to AWS or between AWS services 3. Optimizing AWS costs (right-sizing, Reserved Instances, Savings Plans) 4. Implementing AWS security, compliance, or disaster recovery 5. Troubleshooting AWS service issues or performance problems