Most small cafes and food businesses don't fail because of bad food - they struggle because of inefficient **operations**. Manual order tracking, missed entries, inconsistent billing, and lack of insights create friction every single day. I wanted to solve this. So I built a **cross-platform POS (Point of Sale) app using Flutter** - focused on speed, simplicity, and real-world usability. --- ### The Problem In many small setups: - Orders are tracked manually or loosely - Missed orders = lost revenue - No visibility into daily sales or top items - Billing is inconsistent - Printing is unreliable or unavailable - Apps don't work across devices (Android, desktop, etc.) What they need is not a "complex ERP system". They need: Fast. Simple. Reliable. --- ### The Solution A lightweight POS system that handles: - Order creation (with variants) - Billing & receipt printing - Sales tracking - Backdated entries (for missed orders) - Works across multiple platforms Built entirely using **Flutter**, with Supabase as backend --- ### Core Features

#### 1. Smart Order Management - Add items quickly with search & suggestions - Support for variants (e.g., Steamed & Fried) - Same item with different variants treated separately - Custom items supported (non-menu entries) This allows flexibility without breaking structure. --- #### 2. Accurate Pricing Engine Each order item calculates: Total = Quantity x (Base Price + Variant Price Delta) This ensures: - Transparent billing - Correct totals even with customizations --- #### 3. Receipt Printing (ESC/POS)

One of the most importatnt parts of any POS The app supports: - Bluetoot / USB printers - 58mm / 72mm / 80mm thermal printing - QR-based payments (UPI) - Structured receipts with: - Items - Variants - Totals - Branding And importantly: Reliable printing with chunked writes (avoiding buffer crashes) --- #### 4. Sales & Analytics Dashboard

Not just order-taking -- decision-making The app provides: - Revenue for selected date range - Total orders - Average order value - Top-selling items This helps answer: What sells the most? What earns the most? --- #### 5. Backdated Orders In real operations: Orders get missed. So the app allows: - Selecting a custom date while creating/editing orders - Logging past entries acurately This is critical for - Daily reconciliation - Accounting accuracy --- #### 6. Intelligent Search & Suggestions

Typing: "Cola" Matches: "Coca Cola" With: - Highlighted matches - Price autofill - Fast entry workflow --- #### 7. Adaptive UI (Speed-first Design) Designed for fast interaction: - Draggable cart (collapsed -> expanded) - Sticky total bar - Variant selection sheets - Minimal navigation Everything is optimized for: Tap -> Decide -> Complete --- #### 8. Dark Mode & Theming - Fully theme-driven UI - Consistent design system - Works across light/dark modes --- #### 9. Accesibility Handling Instead of breaking layouts on large font sizes: - Text scaling is clamped intelligently - Layouts use flexible constraints - Critical UI remains usable Balancing: Accessibility × Usability --- #### 10. Sound & Haptics (POS Feedback)

- Click sound on item add - Success / error feedback - Low-latency playback for rapid taps This creates a responsive, tactile experience --- ### Multi-Platform by Design Built with Flutter, the app runs on: - Android, iOS (primary POS device) - Linux, Windows (desktop POS setup) - Web This enables: Same codebase -> multiple environments Perfect for growing businesses --- ### Tech Stack - Flutter -> UI + cross-platform - Supabase (Postgres) -> backedn + RPC - ESC/POS printing -> hardware integration - Hive -> local caching - Custom design system -> consistent UI --- ### Key Engineering Decisions #### 1. RPC-driven backend Complex operations (orders + variants) handled in Postgres: Fewer API calls Better performance Cleaner client code #### 2. Variant-first data model Instead of duplicating items: Menu Item + Variant Groups + Options -> flexible and scalable #### 3. Chunked printing Avoids: Bluetooth buffer overflow crashes -> stable printing experience #### 4. Controlled text scaling Prevents: Broken layouts on high font sizes -> production-ready UI --- ### What This App Solves At its core: It removes friction from daily operations - Faster billing - Fewer missed orders - Better visibility into sales - Reliable printing - Works across devices --- ### What's Next Possible future improvements: - Sales charts (daily / weekly trends) - Category-wise analytics - Export reports (PDF / CSV) - Inventory tracking - Multi-user roles --- This project started as a simple POS tool. But it evolved into: A complete operational system for small food businesses The focus was never just features - It was: Speed, reliability, and real-world usability. If you're building something similar or exploring Flutter for production apps, I'd love to hear your thoughts.

Category: supabase

Flutter POS App