The Well-Architected Framework is one of the more useful things to have internalised for serious AWS work. It comes up in architecture trade-off discussions, CDK design decisions, cost justifications, security reviews - not as a formal checklist but as a consistent vocabulary for reasoning through decisions. I started writing notes to keep the structure clear and they grew into this series.

The Well-Architected Framework whitepaper is the primary source behind all of it. First published in 2015 and updated regularly since, it formalised what AWS Solutions Architects were doing in customer workload reviews into a consistent, documented system. Every revision to the pillars - including the addition of sustainability in 2021 - and the full question set in the Well-Architected Tool originate here. If you work with the framework seriously, this is the document to read.

The six pillars

The pillars are the core of the framework. Each defines a set of design principles and best practices. AWS lists them in this order consistently across the whitepaper, documentation, and the Well-Architected Tool.

Our Systems Run Perfectly, Cheaply, Sustainably

  • Operational Excellence
  • Security
  • Reliability
  • Performance Efficiency
  • Cost Optimization
  • Sustainability
PillarWhat it addresses
Operational ExcellenceRunning and monitoring workloads, improving processes over time
SecurityProtecting data, systems, and assets
ReliabilityRecovering from failures and meeting demand
Performance EfficiencyUsing resources efficiently as demand changes
Cost OptimizationAvoiding unnecessary spend
SustainabilityMinimising the environmental impact of cloud workloads

No pillar operates in isolation - a decision that improves reliability (multi-AZ) has cost implications; a decision that improves performance (larger instance) has sustainability implications. The framework acknowledges these trade-offs rather than pretending they do not exist.

The series

Chapter 1 - The Well-Architected Tool (coming soon)

What the Tool is, how to run a workload review, how to interpret findings, and how the Tool differs from ad hoc pillar checklists.

Chapter 2 - The Six Pillars (coming soon)

An overview of all six pillars - design principles, key questions, and the trade-offs each one introduces. The map before the deep dives.

Chapter 3 - Operational Excellence Pillar (coming soon)

Operations as code, observability, deployment automation, and continuous improvement of operational processes.

Chapter 4 - Security Pillar (coming soon)

Identity, detection, infrastructure protection, data protection, and incident response - the security pillar in detail.

Chapter 5 - Reliability Pillar (coming soon)

Foundations, workload architecture, change management, and failure management - what reliability means in the context of AWS workloads.

Chapter 6 - Performance Efficiency Pillar (coming soon)

Selecting and right-sizing resources, monitoring performance over time, and maintaining efficiency as demand evolves.

Chapter 7 - Cost Optimization Pillar (coming soon)

Expenditure awareness, cost-effective resources, matching supply to demand, and optimising over time.

Chapter 8 - Sustainability Pillar (coming soon)

Measuring and reducing the environmental impact of cloud workloads - right-sizing, Graviton, efficient storage tiers, and sustainability metrics.

Chapter 9 - Lenses (coming soon)

How Lenses extend the framework for specific domains - Serverless, SaaS, Machine Learning, and others - and when to apply them.

Notes

  1. Content is based on the public AWS Well-Architected Framework documentation, not any specific workload or employer environment.