ROI: from stopwatch to dollars

The report is the pitch artifact, and it answers exactly one question: what did the stopwatch say, and what does that buy? It is generated mechanically — just report <run-id> reads a ledger row and the calibrated bench and renders the numbers; nothing is hand-typed.

The three conversions

• Throughput → cores → dollars. A speedup s on a CPU-bound fleet of N cores returns N × (1 − 1/s) cores; at a $/core-hour rate that is an annual saving. Both flow through the speedup's confidence interval, so the report quotes a range.
• Latency → percentile deltas → value. Under replayed load, the p50/p99 latency speedups with their CIs; a p50 service-time reduction maps to throughput capacity for a CPU-bound service.
• Batch windows → wall-clock hours returned to a schedule.

The rule that makes it survive review

Every figure carries its CI and its workload, and the methodology ships inside the report — the interleaved A/B, the pristine baseline, the bootstrap CI, the gates, the calibration. And the number the report tells you to quote is the CI lower bound, never the median:

On a 500-core fleet at $0.04/core-hour, the cJSON service win (+6.2% p50 latency) returns 27.5 cores / $9,621 per year at the CI lower bound (median 29.4 / $10,290). The point estimate is not a promise.

What the report refuses to do

It will not mint a clean dollar figure for a change that wasn't shipped. A row whose verdict isn't accepted, or an accepted row that isn't sanitizer-clean (a pre-gate accept the audit overturned), gets a bold Not shipped banner before any number. That guard was itself added by the adversarial review, which caught the generator pitching the overturned comrak patch. The pitch artifact is held to the same standard as everything else: it cannot claim what wasn't proven.