Cost-Aware Architecture Decisions

Cost-aware architecture is the highest-leverage FinOps work. The decisions made today bound the bill for years.

Why architecture > tactics

A bad architectural choice locks in 2-3x cost for years; tactical optimization recovers 10-20%.

Architecture is the highest leverage.

Four architecture levers

• 1. Multi-AZ vs multi-region.
• 2. Stateful vs stateless.
• 3. Sync vs async.
• 4. Self-host vs managed.

Design-doc cost section

Add a ‘cost section’ to design-doc template: estimated monthly cost; sensitivity to scale; what makes it cheaper.

Reviewers see cost early; bad designs caught in design phase.

Long-term compounding

Year 1: 10% saving from architecture choices. Year 5: 50% saving from compounded right choices.

The discipline pays back over time, not immediately.

Antipatterns

• Cost section as afterthought. Design already locked.
• Architecture without cost-aware reviewers. Misses obvious wastes.
• Cost considered after launch. Migration cost >> design cost.

What to do this week

Three moves. (1) Apply this lever to your highest-spend workload. (2) Measure the dollar impact for one month. (3) Roll the practice out to the next two services if the savings hold.