Overview
An enterprise procurement and inventory application designed specifically for field agents and warehouse supervisors working in basements, rural transit points, and metal warehouses where mobile reception is nonexistent.
The Problem
Agents logging bulk purchase receipts and quality check inspections regularly suffered total data loss whenever internet dropped midway through an order entry, halting dock operations.
The Solution
Engineered an offline-first architecture where every action writes directly to an encrypted local SQLite database first. A background synchronization daemon detects network availability and executes bidirectional delta synchronization.
Key Capabilities
- —100% offline operational capability for catalog search and PO creation
- —Local SQLite database powered by WatermelonDB for instantaneous queries
- —Bidirectional delta synchronization with deterministic conflict resolution
- —High-speed barcode and QR code scanner integration
- —Automated PDF receipt generation and local thermal printer support
Technical Decisions
Local Database as Single Source of Truth
The UI never waits for the network. All reads and writes occur against the local SQLite store, ensuring 60fps responsiveness regardless of connection status.
Timestamp Vector Clock Sync
Built a revision-based delta sync mechanism that only transmits changed records since last sync timestamp, keeping payload sizes under a few kilobytes.
Architecture & Data Flow
React Native UI -> WatermelonDB / SQLite (Encrypted Local) -> Background Sync Engine -> Delta Sync Protocol -> Node.js Backend -> Master PostgreSQL.
My Contribution
Spearheaded the mobile architecture from inception, designed the offline sync algorithm, implemented the local SQLite schema, and built the administrative web portal.
Outcome
Zero data loss recorded across over 50,000 procurement transactions, saving warehouse teams hours of manual reconciliation every week.