Jake McInerney

Case study · Build economics

Move the assumptions yourself

The AI-native workflow case study puts a range on what building the app with Claude saved. Here's the calculator behind it: the measured facts are fixed, the only thing you're changing is the by-hand estimate. Drag the sliders and watch the savings recompute.

The measured facts are reconstructed from Claude Code's own session telemetry and committed to the repo as an aggregates-only snapshot. The dollar cost is self-reported and a floor; the PRs, lines of code, and velocity are git-verifiable — reproducible from the repo's history.

Merged PRs155git-verifiable
Lines of code26,693git-verifiable
Supervised hours~110over 29 days
Claude cost$2,485list price · completed only · self-reported
Claude cost basis
Time saved200 hrs≈ 5.0 weeks
Engineering time avoided$29kby hand: $31,000
Return on spend12.5×hand cost ÷ Claude cost

The by-hand side is an estimate — 155 merged PRs × 2h each, against the ~110 hours actually supervised. The Claude cost is self-reported from session logs and a floor (CI code-review usage isn't counted); only the PRs, lines of code, and velocity are independently reproducible from the repo's git history.