capacity-and-cost-engineering
Capacity and Cost Engineering
Connect demand, performance, reliability, and spend into defensible capacity and cost decisions. This skill models technical capacity, calculates unit cost at the infrastructure level, defines budget and quota controls, requires load/soak evidence for capacity claims, and makes cost-performance tradeoffs explicit — producing evidence that feeds production-readiness launch decisions and constrains or supports site-reliability-engineering SLO choices.
Connected dimensions
Demand (traffic and growth), performance (latency and throughput), reliability (SLOs and error budgets), and spend (cost) are treated as connected dimensions — a change in any one dimension affects the others. The skill's core method is tracing the connection:
| Dimension | Capacity impact | Cost impact |
|---|---|---|
| Demand (traffic, growth rate) | Drives compute, storage, network requirements | Drives baseline and projected spend |
| Performance (latency, throughput target) | Constrains resource headroom per request | Tighter targets increase unit cost |
| Reliability (SLO, error budget) | Requires redundancy, over-provisioning, or isolation | Higher SLOs increase cost non-linearly |
| Spend (budget, cost constraint) | Caps capacity; may force degraded-mode operation | Limits what SLO/performance targets are achievable |
A capacity decision that changes one dimension without modeling the others is incomplete. Every capacity model, unit-cost calculation, and budget decision in this skill must name at least one connection to another dimension with evidence or an explicit assumption.