ClinFlow (Cineflow) Backend Architecture

A scalable, decoupled movie ticket booking backend system built with Node.js and MongoDB. This project utilizes a microservices approach to separate core booking logic from asynchronous tasks, ensuring high availability and seamless user experiences.

The architecture is split into two main components:

1. Core API (ClinFlow): Handles user authentication, theater management, movie scheduling, and ticket booking.
2. Notification Microservice: A standalone background service that asynchronously processes and delivers booking confirmation emails.

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🏗️ Architecture & Workflow

To prevent the main API from hanging while waiting for third-party email servers, the system uses an asynchronous database-polling architecture:

1. A user successfully books a movie ticket via the Core API.
2. The Core API generates an email payload and securely sends an HTTP POST request to the Notification Service.
3. The Notification Service saves the email ticket to a dedicated MongoDB database with a status of PENDING.
4. A scheduled Cron Job (running every 2 minutes) sweeps the database for PENDING tickets.
5. The cron job dispatches the emails using the Resend API.
6. Upon successful delivery, the ticket status is updated to SUCCESS.

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✨ Features

• Secure Authentication: JWT-based user login and registration.
• Movie & Show Management: Endpoints for managing theaters, movies, and showtimes.
• Booking Engine: Transactional ticket booking logic ensuring seat availability.
• Decoupled Notifications: Dedicated microservice for offloading heavy network tasks.
• Resilient Delivery: Automated cron job retries for pending email notifications.
• Cloud-Ready: Fully configured for deployment on modern PaaS platforms (like Render).

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🛠️ Tech Stack

• Runtime: Node.js
• Framework: Express.js
• Database: MongoDB (Mongoose ORM)
• Authentication: JSON Web Tokens (JWT)
• Email Provider: Resend API
• Task Scheduling: node-cron
• Other Tools: dotenv, body-parser

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📂 Repositories

This project is divided across two repositories:

• ClinFlow (Core API): The primary backend handling users, movies, and bookings.
• NotificationService: The email delivery microservice.

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🚀 Installation & Setup

Prerequisites

• Node.js (v16+)
• MongoDB URI (Atlas or Local)
• Resend API Key (starts with re_...)

1. Setting up the Notification Service

Clone the notification repository and install dependencies:

git clone https://github.com/prantaroy11/NotificationService.git
npm install

Create a .env file in the root directory:

PORT=3001
NODE_ENV=development
DB_URL=mongodb://localhost:27017/noti_db
PROD_DB_URL=your_mongodb_atlas_url
RESEND_API_KEY=re_your_api_key_here

Start the notification service:

npm start

2. Setting up the Core API (ClinFlow)

Clone the main repository and install dependencies:

git clone https://github.com/prantaroy11/ClinFlow.git
cd ClinFlow
npm install

Create a .env file in the root directory:

PORT=3000
DB_URL=mongodb://localhost:27017/mba_db
NOTIFICATION_SERVICE_URL=http://localhost:3001/notiservice/api/v1/notifications
JWT_SECRET=your_jwt_secret_key

Start the main server:

npm start

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📡 API Endpoints (Notification Service)

POST /notiservice/api/v1/notifications

Creates a new notification ticket and queues it for delivery. Payload:

{
  "subject": "Your booking is successful!",
  "content": "Your booking for The Monkey King in PVR for 2 seats is confirmed.",
  "recepientEmails": ["user@example.com"]
}

GET /notiservice/api/v1/notifications

Fetches all notification tickets (Pending, Success, Failed).

GET /notiservice/api/v1/notifications/:id

Fetches the status of a specific notification ticket.

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👨‍💻 Author

Pranta Roy * GitHub: @prantaroy11