How can you validate performance and reliability after migration?

• A. Ignore performance until system is fully deployed.
• B. Run load testing, compare baselines, perform canary or blue/green deployments, and monitor with CloudWatch.
• C. Only rely on user reports.
• D. Copy logs to a separate bucket.

Answer: (B)

When validating performance and reliability after migration, use a proactive, measurable approach that combines testing, gradual rollout, and continuous observability. Start with load testing to simulate real traffic and stress the system under expected and peak conditions, then compare the results to pre-migration baselines to identify any regressions in latency, error rates, or throughput. Employ canary or blue/green deployments to route a small portion of traffic to the new environment first, so you can observe real-world behavior and rollback quickly if issues arise. Monitor continuously with a service like CloudWatch to track key metrics (latency percentiles, error rates, throughput, CPU/memory usage, autoscaling activity) and set alarms for anomalies. This combination gives you early visibility into performance and reliability, enabling safe, controlled validation and quick recovery if needed. Relying on waiting until full deployment, or just user reports, or simply copying logs for later analysis, does not provide timely or comprehensive assurance of performance in production.