Cost Awareness

Cost bugs are design bugs. They are cheapest to fix before the first dollar is spent. This skill teaches design-time discipline — choosing the right tier, topology, and access pattern — not post-billing cost reduction tactics.

FinOps Mindset

Cost is a feature requirement, not an afterthought. Treat budget the same way you treat latency and availability SLOs.

• Name a cost budget alongside the performance budget at design time. "Under $X/month at N req/s" is a testable acceptance criterion.
• Cloud bills are emergent: small per-request charges multiply by request volume, retention windows, and replica count in ways that are invisible in local testing.
• Assign cost ownership to the team that controls the resource. Shared cost pools obscure accountability and slow optimization.
• Unit economics clarify decisions: cost-per-request, cost-per-GB-stored, cost-per-active-user. Derive these early; revisit when scale changes by 10×.

Egress and Data Movement