⚙️ Backend Service Name

A production-ready backend service for describe the purpose.

📑 Table of Contents

• About
• How It Works
• Real-World Use Cases
• Features
• Architecture
• Tech Stack
• Project Structure
• Getting Started
• Usage
• Environment Variables
• Database
• Background Jobs
• Caching
• Logging & Monitoring
• Testing
• Docker
• Deployment
• License

🧾 About

Tagline — One sentence describing this service.

Describe what this backend does, what data or operations it owns, and which other systems depend on it.

Example:

The Notifications Service is an internal microservice responsible for delivering email, push, and in-app notifications across all products in the platform. It decouples notification logic from the main application, ensuring delivery reliability via a persistent job queue even during downstream outages.

⚙️ How It Works

Inbound Event (HTTP / Message Queue)
    │
    ▼
Middleware (Auth → Validation → Rate Limit)
    │
    ▼
Controller → Service Layer → Repository
    │                              │
    ▼                              ▼
Async Job Queue (BullMQ)     PostgreSQL / Redis
    │
    ▼
Worker processes job → External API / Email / Push

1. Ingestion: Events arrive via HTTP or a message queue (Kafka / SQS).
2. Validation: Requests are validated against strict Zod schemas before processing.
3. Business Logic: The service layer orchestrates logic without touching HTTP or DB directly.
4. Persistence: All state changes go through the repository layer to PostgreSQL.
5. Async Work: Long-running tasks (emails, file processing) are offloaded to BullMQ workers.

💼 Real-World Use Cases

• Internal Microservice: Other services in the platform POST events here to trigger side effects (emails, push notifications, audit entries) without coupling to delivery logic.
• Webhook Processor: Receives third-party webhooks (Stripe, GitHub) and translates them into domain events for other services to consume.
• Scheduled Jobs: Runs nightly data cleanup, report generation, and billing reconciliation tasks via BullMQ cron jobs.
• Batch Processor: Accepts large CSV uploads, processes them asynchronously, and notifies the requester when done.

✨ Features

• Modular layered architecture (Controller → Service → Repository)
• JWT auth with refresh token rotation
• Background jobs with BullMQ
• Redis caching layer
• Database migrations with Prisma
• Structured logging (Pino)
• Health check endpoint
• Graceful shutdown

🏗️ Architecture

HTTP Request
    │
    ▼
 Router (Fastify)
    │
    ▼
 Middleware (Auth, Validation, Rate Limit)
    │
    ▼
 Controller → Service → Repository
                │
         ┌──────┴──────┐
      PostgreSQL     Redis
           │
        BullMQ Workers

🛠️ Tech Stack

📂 Project Structure

backend/
├── src/
│   ├── config/           # App config & env parsing
│   ├── controllers/      # HTTP handlers
│   ├── services/         # Business logic
│   ├── repositories/     # DB queries (Prisma)
│   ├── middleware/        # Auth, error, validation
│   ├── jobs/             # BullMQ job definitions
│   ├── workers/          # BullMQ worker processors
│   └── utils/            # Shared helpers
├── prisma/
├── tests/
├── Dockerfile
├── docker-compose.yml
└── .env.example

🏁 Getting Started

git clone https://github.com/username/backend.git
cd backend
npm install
cp .env.example .env

# Start Postgres and Redis
docker-compose up -d postgres redis

npm run db:migrate
npm run dev

💡 Usage

HTTP API

# Health check
curl http://localhost:3000/health

# Authenticated request
curl -H "Authorization: Bearer TOKEN"   http://localhost:3000/api/v1/resource

Triggering a Background Job

import { emailQueue } from './jobs/emailQueue';

await emailQueue.add('send-welcome', {
  to: 'user@example.com',
  template: 'welcome',
});

Monitoring Queues

Open Bull Board at

http://localhost:3000/admin/queues

🛠️ Environment Variables

PORT=3000
NODE_ENV=development
DATABASE_URL=postgresql://user:pass@localhost:5432/mydb
REDIS_URL=redis://localhost:6379
JWT_SECRET=your_jwt_secret
JWT_EXPIRES_IN=15m

🗄️ Database

npm run db:migrate      # Run pending migrations
npm run db:rollback     # Rollback last migration
npm run db:seed         # Seed development data
npm run db:studio       # Open Prisma Studio

🔄 Background Jobs

email

notifications

cleanup

🗃️ Caching

Cache keys follow:

{resource}:{id}:{variant}

user:123:profile

📊 Logging & Monitoring

• Logs: structured JSON via Pino
• Health:

  GET /health

  →

  { "status": "ok", "uptime": 12345 }

• Metrics:

  GET /metrics

  (Prometheus-compatible)

🧪 Testing

npm run test
npm run test:integration
npm run test:coverage

🐳 Docker

docker build -t backend-service .
docker-compose up
docker-compose -f docker-compose.prod.yml up -d

🚢 Deployment

npm run build
npm run start

# PM2
pm2 start dist/server.js --name backend-service

📝 License

Distributed under the MIT License. See LICENSE for more information.