ROI Calculator from CRO Request

Build

~2.5 hours

The CRO asks: "Can you build me an ROI calculator for sales to use?" You have no template. You need to spec it, build it, QA it, and document it — from nothing to a fully functional calculator with Apps Script automation and published documentation.

The Slack Message

CRO11:23 AM

Can you build me an ROI calculator for sales to use in demos? I want it in Google Sheets — inputs, outputs, competitive comparison. We need it by end of week. Reps are asking for it in every deal.

The Prompt

No template exists. Start from scratch in Claude Code.

CRO asks: "Can you build me an ROI calculator for sales to use in demos?"

I have no template. Need to spec it, build it, QA it, document it.

(Planner mode) Spec out full ROI model:
- What inputs does sales need to provide?
- What's our pricing structure?
- What are the value drivers?
- What does competition charge?
- What outputs does the calc produce?

Then:
1. Build the sheet with all tabs, formulas, named ranges
2. Push all sheet data + Apps Script files via Gremlin
3. QA: lint for broken formulas, fix any #REF! or errors
4. Create snapshot for version control
5. Publish full documentation to RevOps portal:
   - What this calculator does
   - How to use it (step by step)
   - Input definitions
   - Where to find it

The Cockpit Vision: Claude Code + Gremlin

This isn't cleanup — it's creation. Claude Code is the brain (spec, design, generate). Gremlin is the hands (sync, lint, repair, publish). Full loop: spec → build → QA → document. That's the GTM engineering cockpit made real.

How Gremlin Handles This

Spec (Claude Code)

Planner mode specs the full model: inputs, pricing, value drivers, formulas, outputs

Build (Claude Code)

Generate sheet structure with tabs, formulas, named ranges, and Apps Script

Sync (Gremlin)

Push sheet config + Apps Script files to Google Sheets

QA (Gremlin)

Lint all formulas, fix any #REF! errors, validate edge cases

Snapshot (Gremlin)

Version control the sheet for rollback safety

Document (Gremlin)

Publish "How to Use" guide to Notion with full input definitions

After you paste this prompt, Claude Code:

"I need to build an ROI calculator from scratch. Let me start by speccing out the full model..."

"What inputs does sales need? Current spend, leads/month, hit rate, team size. Outputs: cost per lead, savings, ROI, payback period..."

Generating roi_model.csv with formulas and roi_schema.yaml for validation

- Tabs: Inputs, Calculations, Summary, Comparison

- 23 formulas with named ranges

- Schema validation rules defined

Running

$ g-gremlin write SHEET_ID --tab "ROI Model" --csv roi_model.csv --formulas

Created "Sales ROI Calculator v1.0" with 23 formulas

Running

$ g-gremlin inspect -s SHEET_ID --structure --output .g_gremlin/profile.json

Inspected structure: 4 tabs, 23 formulas, dependency graph mapped

Running

$ g-gremlin lint SHEET_ID --rules "all" --output lint_report.json

Found 2 #REF! errors in Calculations!B12, B15

Running

$ g-gremlin trace SHEET_ID --cell "Summary!C10" --direction upstream --format mermaid --output roi_deps.md

Traced dependencies: C10 ← Calculations!B12 ← Inputs!C5 (found broken ref)

Running

$ g-gremlin lint SHEET_ID --rules "quoting,dead-refs" --fix

Fixed 2 errors. All formulas validated.

Running

$ g-gremlin schema-validate SHEET_ID --schema roi_schema.yaml --strict

Schema validation passed: all cells match expected types and references

Running

$ g-gremlin snapshot create SHEET_ID --name "roi-calc-v1"

Snapshot saved: .g_gremlin/snapshots/roi-calc-v1.json

Running

$ g-gremlin docs publish --provider notion --template roi_docs.md --data '{"title":"ROI Calculator"}' --external-id roi-doc-1 --apply

Published documentation with inputs, outputs, and usage guide

Done. Calculator ready, schema validated, documentation published.

Output Artifacts

Google Sheet: Sales ROI Calculator

Inputs — Customer data entry with validation
Calculations — Hidden formula logic
Summary — Executive dashboard
Apps Script — Dropdown handlers, formatting

Notion Page: How to Use

What it does — Purpose and outputs
Step by step — How to use in demos
Input definitions — What each field means
Where to find it — Link to sheet

Also created: QA report (0 errors), version snapshot for rollback, config YAML for future edits

Results

Tabs built

Formulas created

Errors found & fixed

0 errors

QA report

Build time: 2h 15m

vs ~2 days manual (spec, build, test, document separately)

Try This Workflow

Start with the quickstart guide, then build your own calculators and tools.

View Quickstart Guide More Playbooks