Cost & FinOps
General material on the economics of an architecture.
4 to work through
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intermediate
A platform's cloud spend grows faster than traffic for six quarters, with no single team responsible. Why do cost-reduction sprints fail to hold, and what is the reframing that works?
2 min answer -
intermediate
Finance wants to cut cloud spend by committing to one-year and three-year reservations. What do you commit to, and what could go wrong?
2 min answer -
intermediate
The cloud bill has tripled in six months while traffic grew 40%. How do you find out why, and what do you expect to find?
2 min answer -
advanced
A design review presents a new event-driven platform. What cost questions do you ask before approving it?
2 min answer
9 terms in this topic
Architecture Cost Model
A calculation, made during design, of what an architecture will cost to run at expected and at peak volume.
practiceChargeback and Showback
Attributing cloud cost to the teams that generate it — either informationally (showback) or by moving it onto their budget (chargeback).
conceptCloud Pricing Models
The purchase options for cloud compute — on-demand, committed use, and spot — which differ by up to 90% for identical hardware.
metricCost per Request
The fully-loaded infrastructure cost of serving one request, and the unit that makes architectural cost decisions comparable.
conceptCost vs Reliability Trade-off
The non-linear relationship between availability and spend, which makes each additional nine roughly an order of magnitude more expensive.
case-studyDropbox's Move Off S3
Dropbox moved the majority of its file storage off Amazon S3 onto custom infrastructure, reporting savings that its S-1 filing put at roughly $75 mil…
conceptEgress Cost
The charge for moving data out of a cloud provider or across its zones and regions — usually the least-anticipated line on a cloud bill.
practiceFinOps
The practice of giving engineering teams visibility into and accountability for the cost of what they build and run.
metricTotal Cost of Ownership
The full lifetime cost of a capability, including the people, operations, upgrades and exit that a licence comparison leaves out.
Neighbouring topics
Total Cost of Ownership
Lifetime cost including people, operations, upgrades and exit.
Cloud Pricing Models
On-demand, committed and spot, and the crossover arithmetic.
Reserved & Committed Capacity
Committing the baseline, laddering terms, and expiry as a silent failure.
Spot & Interruptible Capacity
Deep discounts for work that can be interrupted and resumed.
Unit Economics
Cost per request, per tenant, per transaction — the actionable number.
Cost per Request
Fully-loaded per-unit cost, including the lines usually left out.
Storage Costs
Tiering, lifecycle policies, retrieval charges and minimum durations.
Network & Egress Costs
Cross-zone and cross-region transfer that appears on no diagram.
Compute Optimisation
Instance families, utilisation, and architecture that wastes less.
Rightsizing
Matching provisioned resources to observed demand rather than to a guess.
Cost Allocation
Tagging enforced at provisioning, and apportioning shared costs.
Showback & Chargeback
Making teams see, or own, the cost of what they run.
Architecture Cost Modelling
Pricing a design before building it, at expected and at ten times volume.
Cost vs Reliability
Each nine costing an order of magnitude, and pricing the failure instead.
Observability Cost
Telemetry bills, cardinality control and retention tiering.
Licence & Vendor Costs
Per-core, per-seat and per-environment terms that shape designs.
FinOps Practice
Inform, optimise, operate — and cost as a design-review criterion.
Waste Elimination
Idle environments, orphaned volumes, forgotten instances, dead data.
Cost Governance
Budgets, anomaly alerts, quotas and preventive policy.