The Well-Architected Framework
The six pillars AWS uses to define a good architecture — and how to match each pillar to its exam keywords.
The AWS Well-Architected Framework is a set of best practices for designing cloud workloads, organized into six pillars. The exam loves asking you to match a scenario or design principle to its pillar, so focus on each pillar's signature keywords.
The six pillars
| Pillar | Core question | Keywords to spot |
|---|---|---|
| Operational Excellence | Can you run, monitor, and improve the system? | Runbooks, small reversible changes, operations as code, learn from failures |
| Security | Is data and infrastructure protected? | Least privilege, encryption at rest/in transit, traceability, IAM |
| Reliability | Does the system recover from failure? | Multi-AZ, auto scaling, backups, recovery testing, avoiding single points of failure |
| Performance Efficiency | Are you using the right resources efficiently? | Right-sizing, serverless, experimenting with new instance types, going global |
| Cost Optimization | Are you avoiding unnecessary spend? | Pay only for what you use, measure spend, decommission idle resources, Savings Plans |
| Sustainability | Are you minimizing environmental impact? | Energy efficiency, maximizing utilization, managed services to share resources |
Remember "SO CRPS" (Security, Operational excellence, Cost, Reliability, Performance, Sustainability) — or picture a well-built house: locks (security), a maintenance schedule (operational excellence), storm resistance (reliability), efficient appliances (performance), a sensible budget (cost), and solar panels (sustainability).
Reliability vs Performance trips people up: recovering from failure or removing single points of failure → Reliability. Choosing the right instance type or using serverless for efficiency → Performance Efficiency. And anything about *turning off idle resources* → Cost Optimization.
The free AWS Well-Architected Tool in the console lets you review your workloads against these pillars and produces an improvement plan. Related: the AWS Cloud Adoption Framework (CAF), covered in the next lesson, guides the organizational side of moving to the cloud.
A design ensures a workload automatically recovers when an Availability Zone fails. Which Well-Architected pillar does this reflect?