Bills a counter and sends the invoice to the customer on WhatsApp before they leave the shop.
Enterprise billing & POS with automated WhatsApp invoicing, inventory, loyalty and barcode generation — Flutter over Firebase and Node.js, on Android & Windows.
Dectwin Billing POS handles complete business billing workflows — party registration, inventory, promotional offers, loyalty points and barcode generation — with automated WhatsApp invoice delivery. Built with Flutter over Firebase and Node.js for Android and Windows, with PDF/Excel reporting and a real-time analytics dashboard.
The problem
Businesses struggled with manual billing, inventory tracking and customer communication.
The solution
Built a POS system with automated WhatsApp invoicing, real-time inventory and loyalty.
Technical stack
Frontend
Flutter
Backend
Node.js
Kotlin
Data
Firebase
SQFlite
Infrastructure
REST APIs
WhatsApp API
Core features
Automated WhatsApp invoicing
Party registration & management
Inventory management
Promotional offers & loyalty points
Barcode & QR generation
PDF/Excel reporting and analytics
Results & impact
Cut report complexity by ~90% and streamlined operations across multiple businesses.
