cost-reviewlisted

# Cost Review ## Procedure 1. **Attribute.** Break spend by team, service, and environment. Untagged spend is finding number one — you cannot optimise what you cannot attribute. 2. **Find the drivers.** Rank by absolute spend, then look for the usual suspects: | Driver | Typical cause | |---|---| | Cross-zone / egress traffic | Chatty services split across zones; no locality awareness | | Storage class | Everything on hot storage forever; no lifecycle policy | | Idle capacity | Non-production running nights and weekends | | Over-provisioning | Sized for a peak that never arrived, never revisited | | Managed service premium | Paying for an operator you do not need at this scale | | Log and metric volume | Debug logging left on; high-cardinality labels | | LLM tokens | No caching, oversized model for the task, unbounded context | 3. **Compute unit economics.** Cost per request, per tenant, per model call. Totals hide everything — a bill that doubled while traffic tripled is a *win*. 4. **Model at scale.** What does this cost at 10x? A design that is cheap today and ruinous at scale is rejected now, while changing it is still cheap. 5. **Recommend with numbers.** Each item: measured monthly saving, effort, and the performance or reliability risk it introduces. ## Output | Finding | Monthly cost | Proposed change | Saving | Risk | Effort | ## Worked example **Weak — unactionable, and quietly dangerous:** ``` - NAT Gateway costs are