Blind Insight - Platform Engineer Coding Challenge

This project is a secure document storage and retrieval API built with Express.js and TypeScript, simulating a simplified encrypted storage system with authentication, audit logging, and encrypted data at rest.

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🛠️ Tech Stack

• Backend: Node.js, Express.js, TypeScript
• Auth: JWT (JSON Web Tokens)
• Database: MongoDB (supports both local and Atlas)
• Encryption: AES-256-CBC with Node.js crypto
• Testing: Jest, Supertest
• Docs: Optional Swagger support
• Deployment: Docker-ready (optional)

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🚀 Features

• 🔐 JWT Authentication
• 📄 Encrypted Document Storage
• 📥 Document Retrieval with Decryption
• 📝 Metadata Filtering
• 🛡️ Role-Based Access to Audit Logs
• 📊 Audit Logging for all API activity
• ✅ Unit tests for core functionality

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📦 Installation

npm install

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🔐 Environment Variables

Create a .env file in the root directory:

PORT=3000
MONGODB_URI=mongodb://localhost:27017/secure_document_storage
JWT_SECRET=secret-key
SECRET_KEY=secret-key

To use MongoDB Atlas, replace MONGO_URI with your Atlas URI.

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🧪 Run the App

npm run dev

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🧪 Run Tests

npm test

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🧪 API Endpoints

🔐 Auth

POST /api/auth/login

Request:

{
  "username": "user1",
  "password": "password123"
}

Response:

{
  "token": "JWT_TOKEN"
}

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📄 Documents

• POST /api/documents – Store a document (with JWT)
• GET /api/documents – List documents of user
• GET /api/documents/:id – Retrieve a single document

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📊 Logs

GET /api/logs

Requires admin role.

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🧱 Design Choices

• Encryption: Used crypto module (AES-256-CBC)
• Auth: JWT-based for stateless validation
• Audit Logging: Captures every access, success/failure, and user info
• Database: Swappable between local MongoDB and MongoDB Atlas

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🐳 Docker Support (Optional)

docker build -t code-challenge .
docker run -p 3000:3000 code-challenge

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📁 Project Structure

src/
├── __tests__/
├── config/
├── controllers/
├── lib/
├── middlewares/
├── models/
├── routes/
├── services/
├── swagger/
├── app.ts
├── server.ts
└── swagger.ts