An App Built for One: Why a Devpost Skill Pack Made Me Spec It Anyway

Description and use

Cuenta is an app that replaced paper bookkeeping in a small bakery, providing a digital workflow for inventory counting, invoicing, and ledger management.

Problem

Eileen’s wholesale bakery relied on a single yellow notebook for inventory, invoices, and payments; losing it exposed the fragility of paper‑based bookkeeping.

Outcome

Cuenta replaced a fragile paper system with a reliable digital workflow, preventing data loss, ensuring accurate invoicing, and providing a single source of truth for inventory and payments.

Workflow

• 1. Interview with Devpost Learn skill pack to generate planning documents.
• 2. Review and approve scope, PRD, and spec files.
• 3. Claude Code builds the app in 8 slices, each checked before proceeding.
• 4. Agent flags decisions for review (e.g., server clock, price linking, demo vs. real goals).
• 5. Implement count, deliver, invoice, ledger, and customer screens.
• 6. Test email sending and PDF generation, adjust UI feedback.
• 7. Deploy to Vercel, ensuring UTC time handling and price immutability.
• 8. Verify functionality with mock data and real customer accounts.

Evidence

Cuenta is a small app for my wife's wholesale bakery: count what's left on each cafe's shelf, build the delivery, print and email her branded invoice, and see who owes what.

Source

Built from an empty folder to a working app in about 20 hours, sleep included, using the Devpost Learn skill pack.

Source

The interview pushed back, and it caught things I would have paid for later: The server clock, Linked prices, Two finish lines, Count and invoice are different jobs.

Source

Every slice report from the agent ended with a section called "Calls I made that you should check."

Source