The six pillars
| Pillar | Optimizes for |
|---|---|
| Operational Excellence | Running and monitoring systems; continual improvement of processes (IaC, small reversible changes, observability). |
| Security | Protecting data and systems — least privilege, encryption, traceability, defence in depth. |
| Reliability | Recovering from failure, scaling to meet demand (multi-AZ, automated recovery, backups). |
| Performance Efficiency | Using resources efficiently; right-sizing and adopting newer technologies. |
| Cost Optimization | Avoiding unneeded cost — right pricing models, eliminating waste, measuring spend. |
| Sustainability | Minimizing environmental impact of cloud workloads (added 2021). |
A way to remember them
Mnemonic
"Performance, Operational excellence, Reliability, Security, Cost, Sustainability" — a common aid is "The Pillars Of Reliable Systems Cost-effectively Sustain". Security and Reliability are the two examiners stress most.
Exam traps
- Forgetting Sustainability. It was added in 2021 — older material lists only five pillars.
- Confusing Reliability and Performance Efficiency. Reliability = recover/scale to meet demand; Performance = use resources efficiently.
- Treating it as mandatory rules. It's a set of best-practice questions and trade-offs, not hard requirements.
Test yourself
4 quick questions — tap an answer to check it instantly. Nothing is sent anywhere.
1. Which pillar was added most recently (2021)?
Answer: C. Sustainability became the sixth pillar in 2021.
2. Which pillar covers recovering from failure and scaling to meet demand?
Answer: B. Reliability = recovery and meeting demand; Performance Efficiency = using resources efficiently.
3. How many pillars are there in total?
Answer: C. Six pillars since 2021.
4. Least privilege and encryption fall under which pillar?
Answer: A. Protecting data and systems is the Security pillar.
Sources
- Amazon Web Services — AWS Well-Architected.
- AWS official documentation and the AWS Certified Solutions Architect exam guide.
Reference summary only. "AWS" is a trademark of Amazon. Confirm current details in the official AWS documentation.