InspectSync: Precision Field Operations Platform

InspectSync is a robust, enterprise-grade field inspection platform designed for high-stakes environments where data integrity and offline reliability are non-negotiable. It solves the critical "Field Data Gap" by enabling seamless operations in zero-connectivity zones through an advanced, version-controlled synchronization engine.

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🏗️ System Architecture

InspectSync is built on a modern, distributed architecture designed for low latency and high reliability.

graph TD
    subgraph "Client Layer (Flutter Mobile App)"
        UI[Tactical UI] --> Controller[Sync Controller]
        Controller --> LocalDB[(Drift SQLite)]
        Controller --> SyncEngine[Sync Engine]
    end

    subgraph "Communication"
        SyncEngine <==> API[REST API / Express]
    end

    subgraph "Server Layer (Node.js Backend)"
        API --> Service[Sync Service]
        Service --> DB[(PostgreSQL / Prisma)]
        Service --> Cache[(Redis / BullMQ)]
        Service --> Storage[AWS S3 Media]
    end

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Features

1. Optimistic Offline Engine

Engineers can perform full inspections without an internet connection. All changes are logged to an internal Sync Queue (Idempotent) and automatically synchronized when connectivity is restored.

2. Intelligent Conflict Resolution

The system employs a version-based concurrency model. Mismatches between local and server records are detected during the "Push" phase, allowing users to perform side-by-side resolution to ensure no data is lost.

3. Tactical "Obsidian Command" Design

The UI is optimized for field visibility, featuring high-contrast dark modes, large touch targets (min 48dp), and a "no-distraction" layout philosophy.

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🛠️ Technology Stack

Component	Technology	Why?
Frontend	Flutter (Dart)	Multi-platform consistency & high-performance UI.
Local Storage	Drift (SQLite)	Reactive, type-safe local persistence.
Backend	Node.js (Express 5)	Scalable, event-driven API architecture.
ORM	Prisma	Type-safe database operations and automated migrations.
Database	PostgreSQL	Relational integrity for complex inspection models.
Task Queue	BullMQ + Redis	Robust background processing for batch sync logs.
Media	AWS S3	Secure, scalable storage for private inspection evidence.

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🚀 Quick Start

Prerequisites

• Flutter SDK (3.22+)
• Node.js (v20+)
• PostgreSQL & Redis (Running locally or via Docker)

Setup

1. Clone the repository:

   git clone https://github.com/shouryasonu/inspectSync.git
   cd inspectSync

2. Backend Setup:

   cd inspect-backend
   npm install
   # Configure .env (see .env.example)
   npx prisma db push
   npm run dev

3. Frontend Setup:

   cd ../inspectsync
   flutter pub get
   flutter run

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📂 Project Structure

• /inspectsync: The Flutter mobile application.
• /inspect-backend: The Node.js REST API.

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🛡️ Operational Resilience

• Idempotent Sync: Every local change has a unique idempotencyKey to prevent duplicate processing.
• Delta Pulls: The client only pulls records changed since the last_synced_at timestamp, minimizing bandwidth usage.
• Presigned Security: Media is never public; the system uses 24h AWS Presigned URLs for secure temporary access.

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Designed with ❤️ for Field Engineers by Shourya Sonu

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📜 License

This project is licensed under the MIT License. See the LICENSE file for details.