1. WAF Review Process

A WAF review is a structured assessment of an existing workload against five pillars. Steps:

1. Scope – Identify the workload boundary (resources, teams, SLAs).
2. Assess – Answer pillar-specific questions (60–100 per pillar).
3. Prioritize – Score findings by business impact and effort.
4. Remediate – Create backlog items with clear owners and timelines.
5. Iterate – Re-assess quarterly; integrate into deployment gates.

2. Reliability Pillar

• Failure Mode Analysis (FMA) – Enumerate every component failure, assign probability & blast radius, design mitigations.
• SLA Targets – Composite SLA = product of individual SLAs. Use Availability Zones & paired regions to exceed 99.99%.
• Redundancy – Active-active (Traffic Manager) or active-passive (ASR). Stateless tiers scale independently.
• Testing – Chaos experiments (Azure Chaos Studio), game days, failover drills, load testing pre-production.

3. Security Pillar

• Zero-Trust – Verify explicitly, least-privilege access, assume breach. Every request authenticated & authorized.
• Defense in Depth – Layers: identity → network (NSG, Firewall) → compute (host hardening) → data (encryption).
• Identity-First – Managed identities eliminate secrets; Conditional Access enforces context-aware policies.
• Data Protection – Encryption at rest (SSE, CMK) & in transit (TLS 1.2+); classify data; apply DLP and purview labels.

4. Cost Optimization Pillar

• Right-Sizing – Azure Advisor recommendations; resize or deallocate underused VMs.
• Reservations & Savings Plans – 1-yr or 3-yr commits for predictable workloads (up to 72% savings).
• Monitor Waste – Orphaned disks, idle IPs, over-provisioned App Service plans; use Cost Management budgets & alerts.
• Chargeback/Showback – Tag resources by team/project; allocate shared costs (hub network, platform services).

5. Operational Excellence

• IaC – All resources in Bicep/Terraform; no portal drift; drift detection via what-if.
• CI/CD – Automated pipelines with linting, unit tests, integration tests, approval gates.
• Monitoring – Golden signals (latency, traffic, errors, saturation); dashboards per team; actionable alerts.
• Incident Response – Runbooks, on-call rotation, blameless post-mortems, auto-remediation via Logic Apps.
• Safe Deployments – Canary, blue-green, ring-based rollout; feature flags; automatic rollback on health degradation.

6. Performance Efficiency

• Scaling – Autoscale rules (VMSS, App Service); scale-out preferred over scale-up for resilience.
• Caching – Azure Cache for Redis; CDN for static assets; application-level output caching.
• Async Patterns – Queue-based load leveling (Service Bus); event-driven (Event Grid); decouple hot paths.
• CDN & Edge – Front Door for global acceleration; edge compute for latency-sensitive APIs.
• Data Partitioning – Shard databases (Cosmos DB partition keys); separate OLTP from analytics (CQRS).

7. Trade-offs Between Pillars

8. WAF Assessment Tool

1. Access – Navigate to aka.ms/waf; sign in; select or create a workload profile.
2. Answer – Respond to pillar-specific questions; mark N/A for irrelevant items.
3. Review Results – Score per pillar (0–100); drill into specific recommendations.
4. Export & Track – Export as PDF/CSV; link findings to Azure DevOps work items.
5. Prioritize – High-impact / low-effort items first (quick wins); schedule deep fixes in sprints.

Tip: Run assessments before major releases and after architecture changes. Compare scores over time to show continuous improvement.

11. Knowledge Check