AWS Well-Architected Framework six pillars explained
The AWS Well-Architected Framework is a set of best practices and questions for checking how well a workload is built. It has six pillars: operational excellence, security, reliability, performance efficiency, cost optimization and sustainability.
The six pillars in one line each
Operational excellence: support development and run workloads effectively, gain insight into their operations, and continuously improve supporting processes and procedures to deliver business value.
Security: use cloud technologies to protect data, systems and assets in a way that can improve your security posture.
Reliability: a workload performs its intended function correctly and consistently when it is expected to. This includes operating and testing it through its whole lifecycle.
Performance efficiency: use computing resources efficiently to meet system requirements, and keep that efficiency as demand changes and technologies evolve.
Cost optimization: run systems that deliver business value at the lowest price point.
Sustainability: keep improving sustainability impacts by reducing energy consumption and increasing efficiency across all components of a workload.
Trade-offs between pillars
AWS says you make trade-offs between pillars based on business context. For example, a development environment might give up some reliability to lower cost and sustainability impact. A mission-critical system might accept higher cost to improve reliability.
Security and operational excellence are the exception. AWS says they are generally not traded off against the other pillars.
General design principles
The framework also lists general design principles that apply across the pillars: stop guessing your capacity needs, test systems at production scale, automate with architectural experimentation in mind, consider evolutionary architectures, drive architectures using data, and improve through game days.
Testing at production scale is cheaper in the cloud because you create the test environment on demand, pay only while it runs, and then decommission it.
Where the exam catches people
Believing there are five pillars: sustainability is the sixth pillar of the framework.
Believing reliability means fast performance: reliability is doing the intended function correctly and consistently; using resources efficiently as demand changes is performance efficiency.
Believing every pillar can be traded off: AWS says security and operational excellence are generally not traded off against the other pillars.
Believing cost optimization means the cheapest option: it means delivering business value at the lowest price point.