Explain the AWS Well-Architected Framework and its pillars.

The AWS Well-Architected Framework is a set of best-practice guidelines for designing reliable, secure, efficient, and cost-effective cloud workloads.

• Operational Excellence — automate change, monitor everything, learn from failure (CloudWatch, Systems Manager, runbooks).

• Security — least privilege, defense in depth, encrypt in transit and at rest (IAM, KMS, GuardDuty).

• Reliability — Multi-AZ, auto-scaling, backup and recovery, chaos engineering with Fault Injection Simulator.

• Performance Efficiency — pick the right instance family, use caches (CloudFront, ElastiCache), benchmark regularly.

• Cost Optimization — match supply to demand, use Spot/Savings Plans, right-size with Compute Optimizer.

• Sustainability — added in 2021 — minimize carbon by right-sizing and using Graviton.

Use the Well-Architected Tool in the console to score workloads against the six pillars and get prioritized recommendations.