Which AWS service should you use to monitor performance and reliability post-migration?

• A. IAM
• B. CloudTrail
• C. CloudWatch
• D. SageMaker

Answer: (C)

Monitoring performance and reliability after migration requires a centralized way to collect operational metrics, logs, and alerts across AWS resources and your applications. CloudWatch provides exactly that. It automatically gathers metrics from many AWS services, supports publishing custom application metrics, and stores logs. You can build dashboards to visualize latency, error rates, resource utilization, and throughput, and set alarms that alert you or trigger automated responses when performance slips or failures occur. This ongoing visibility is essential to ensure the migrated environment stays healthy and issues are detected and addressed quickly. Other services serve different purposes: IAM handles access management, CloudTrail records API activity for auditing, and SageMaker focuses on machine learning workloads. So CloudWatch is the right tool for post-migration monitoring of performance and reliability.