Continuous Improvement for Existing Solutions Study Guide — SAP-C02

Continuous Improvement for Existing Solutions – SAP-C02 Study Guide

This domain accounts for 25% of the exam and covers improving workloads that already run on AWS across all Well-Architected pillars — operational excellence, security, reliability, performance, and cost. Questions typically describe an existing architecture with a weakness (a single point of failure, an over-provisioned fleet, embedded credentials) and ask for the best remediation. Recognize the anti-pattern and apply the standard fix.

Reliability Improvements

• Remove single points of failure — replace a single instance with an Auto Scaling group across AZs behind a load balancer with health checks.
• Regional resilience — for a revenue-critical service, introduce a multi-Region strategy (active-passive with Route 53 health-check failover, or active-active). Same-Region redundancy can't survive a Region loss.
• Responsive scaling — target-tracking/predictive scaling and warm pools to react to spikes; tune metrics and cooldowns.

Performance Improvements

• Read scaling — add read replicas to offload reporting from the transactional primary.
• Caching — ElastiCache (Redis/Memcached) for frequently read, slowly changing data; CloudFront for global content delivery and origin offload.
• Right-sizing — match instance types to actual utilization.