Point of sale & cash control
Sales, cash drawers, shift closes and audit trails that show who handled the money and when.
Available for freelance projects · English / Spanish
César García
Munive
Full-stack developer · Operations software for small businesses
I build the systems small businesses run on — point of sale, inventory, memberships and collections — for owners who need to know where every sale, every bill and every product went.
Three B2B systems in production, designed, built and maintained end to end by me. All three handle real money every day for businesses with employees, inventory and cash.
Shift close · Register 2
Live
Expected
•••••
hidden until count
Counted
$1,284.50
Cashier
A.
Audit logappend-only
- 10:41 AM Cash count — expected hiddenCashier: A. —
- 10:20 AM Cash drop to safeCashier: A. · witness: M. $200.00
- 9:14 AM Sale #1042Cashier: A. · 3 items $38.50
- 9:02 AM Drawer openedCashier: A. · float $150.00
Every movement attributedSynced
3
Systems in production, all handling real money
14days
From launch to first paying client
1year
Prepaid upfront by a client
544
Automated tests in a single backend
Services
What I build
Inventory & operations
Stock where every movement is recorded, barcode labels, multi-location catalogs, route and consignment sales.
Memberships & recurring billing
Access control, subscriptions, Stripe payments and automated reminders over WhatsApp and email.
Integrations & hardware
Payment gateways, WhatsApp Cloud API, third-party reconciliation, thermal printers, laser scanners and turnstiles.
Work
Three systems in production
Retail point of sale · In production
Klamit
Result
Client runs two locations, is opening a third, and prepaid a full year.
A point of sale built to answer the question most POS systems ignore: who had the money, when, and what should have been there.
- Blind cash counts: cashiers count the drawer without seeing the expected total
- Every movement attributed to a cashier, with an audit log that can't be erased
- Mobile top-ups certified with five national carriers, reconciled automatically every five minutes
- Volume pricing calculated inside the transaction — a sale request can't carry its own prices
- Check-digit SKUs printed on thermal label printers and read by laser scanners
Fastify
Prisma
PostgreSQL
React
Vite
Tailwind
Capacitor (Android)
Railway
Vercel
Warn, don't block. A system that blocks legitimate work gets bypassed — and a bypassed system audits nothing.
Design principle
From the field
The barcode scanner was corrupting SKUs because the scanner and the tablet used different keyboard layouts. Instead of asking every client to reconfigure their hardware, the app generates candidate codes and lets the check digit decide which one is real. It recovers from swapped characters and lost separators without ever guessing — covered by 76 tests, including a sweep of 200 generated SKUs.
Gym & academy management · In production · 2 clients
Zoshia Tech
Result
First paying client 14 days after launch. Largest client: ~300 registered members, 137 active memberships.
Management for gyms and academies: QR access control, memberships, a product store and automated reminders.
- QR check-in and check-out, with physical turnstile support
- Memberships, plans and a point of sale for memberships and store products
- Revenue dashboard and Excel reports
- Automated WhatsApp and email reminders for expirations, configurable per client
- Public bookings and recurring billing with Stripe
Node.js
Express
PostgreSQL
React
Vite
Stripe
Resend
Cloudinary
Sentry
WhatsApp Cloud API
Route distribution & consignment · In production
Zodovok
Result
Paid setup and renewal — the client runs her daily operation on it on her own.
Sales control for small distributors who deliver by van and sell on consignment — a market that ERPs and route software don't serve.
It started with a real loss: no way to prove what had been delivered. It wasn't built to digitize — it was built to prove.
- Paste a customer's WhatsApp message and AI turns it into an order against the real catalog; anything ambiguous goes to a review screen
- Partial deliveries recorded visit by visit, with permanent history
- Three-layer pricing (base, trusted-customer list, per-customer exceptions) plus tiered volume pricing
- Partial payments, customer balances and accounts receivable
- Inventory where stock never changes without a recorded movement
TypeScript (strict)
Node.js
Hono
Prisma
PostgreSQL
React
Vite
PWA
Railway
Vercel
Principles
- Money is never a float
- Stock never moves without a record
- AI proposes, a human confirms
Quality
544 backend tests and 40 frontend tests. Additive migrations verified against production with before-and-after snapshots, and tested restores.
How I build
Software for businesses where the numbers have to add up
-
Traceability over interface.
When a business handles cash, the most important screen is the one that shows what actually happened.
-
Warn, don't block.
Controls people work around are worse than no controls. I make every action visible instead.
-
Production is sacred.
Additive migrations, snapshots before and after, tested backups, guarded destructive scripts.
-
AI proposes, people decide.
I use AI where it saves time, never where it could silently change money or stock.
-
You talk to the builder.
I design, build, deploy and support the system myself — no handoffs, no account managers.
About
Who am I?
I'm César García Munive, a full-stack developer based in Toluca, Mexico. I work end to end: I sit down with the business owner, design the data model, build the backend and frontend, deploy, and stay on to support it.
I learned by building software for real businesses — a retail store, gyms and a route distributor — and by solving what came up in production. That's why my systems care more about whether the cash drawer adds up than about how the dashboard looks.
I work in English and Spanish, on Central Time (UTC-6), with full overlap with US business hours.
📍 Toluca, Mexico · UTC-6
Contact
Let's talk about your business
Need a system to control sales, inventory, memberships or cash — or a developer who has already shipped to production? Tell me what you're working on. I usually reply within 24 hours.