Inventory + POS for Retail
Unified offline sales with cloud inventory for real-time stock visibility.
The Context
A growing retail chain with 5 locations and roughly 50 SKUs per category was using standalone, legacy POS machines that did not sync inventory across stores. Each store had its own terminal and no shared view of stock, leading to frequent stockouts in some locations and over-ordering in others. HQ had to call stores or visit in person to get sales and inventory numbers.
The Challenge
"Management lacked real-time visibility into sales and stock levels. Cashiers dealt with slow, clunky interfaces and could not look up products quickly during rushes. Internet outages—common in one of the store locations—would completely halt sales. End-of-day reconciliation was manual and error-prone, and reorder decisions were based on gut feel rather than data."
The Solution
We built a modern, cloud-connected Web POS that works as a PWA on store tablets and PCs. It functions seamlessly offline: sales and returns are stored locally and synced when the connection restores. We paired it with a centralized inventory and analytics dashboard for HQ so buyers and managers could see real-time stock and sales trends across all locations.
Point of Sale (POS)
- Fast, touch-optimized cashier interface with quick product search and barcode scan
- Barcode scanner integration (USB HID and Bluetooth)
- Offline-first architecture: full sales and returns when disconnected; sync when back online
- Digital receipts (email/SMS) and thermal receipt printing
- Role-based access (Cashier, Supervisor, Manager) with override logs
- Returns and exchanges with reason codes and inventory correction
- Split payments and cash drawer tracking
Inventory & Analytics
- Real-time multi-store stock visibility and transfer requests between stores
- Automated low-stock alerts and reorder reports by category and vendor
- Sales analytics dashboard (daily, weekly, seasonal trends and top movers)
- Centralized product catalog with variants, barcodes, and cost/sell prices
- Audit trail for inventory adjustments and variance reports
System Interface
Touch-optimized POS interface
Multi-store inventory overview
Sales trends and analytics
Offline mode synchronization queue
Business Outcomes
Reduced stockouts by 45% across all locations with better visibility and reorder reports
Sped up average checkout time by 30% with the new interface and scanner flow
Achieved 100% uptime during local internet outages thanks to offline-first design
Reduced end-of-day reconciliation time from over an hour to under 15 minutes
Architecture Notes & Lessons
Building a reliable offline-first sync engine was the hardest technical challenge. We implemented strict conflict resolution: last-write-wins for simple data and explicit rules for inventory counts when multiple offline registers came back online. We also learned to test on real thermal printers and low-end tablets early—device quirks caused more bugs than the core sync logic.
Architecture
The POS client is a Progressive Web App (React + Vite) with IndexedDB for offline transaction and product cache storage. A background sync worker queues sales and inventory updates and retries on failure. The central Node.js/PostgreSQL backend handles auth, product master data, and consolidated reporting; conflict resolution uses last-write-wins for simple fields and explicit rules for inventory counts.