Nihira, A Real-Time Chat Application

Nihira is a scalable, modular, and real-time chat application built using a microservices architecture. Designed for performance, security, and extensibility, Nihira mimics production-grade chat systems like WhatsApp, Slack, and Discord—while offering transparency in design and educational value.

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🚀 Features

• ⚡ Real-time Messaging using Socket.IO
• 📦 Microservices Architecture (Modular & Scalable)
• 📨 Event-Driven Communication using Kafka
• 🔀 Efficient Pub/Sub with Redis
• 🔐 Secure Authentication with JWT
• 🛠️ Modern Tech Stack with best practices in scalability, fault-tolerance, and maintainability

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🧱 Architecture Overview

Client (React) <---> Gateway Service (Express + JWT Auth)
                             |
                             V
                +-------------------------+
                |                         |
      Message Service <--> Kafka <--> Notification Service
                |
             MongoDB
                |
             Redis Pub/Sub

• Gateway Service: Handles authentication, token verification, and API routing.
• Message Service: Stores and routes messages, interacts with MongoDB, Kafka, and Redis.
• Notification Service: Consumes Kafka topics and handles notifications.
• Kafka: Acts as the backbone for scalable event communication.
• Redis: Used for pub/sub and temporary session/state management.

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🧰 Tech Stack

Layer	Technology
Frontend	React
Backend	Node.js + Express
Real-time Comm	Socket.IO
Message Broker	Apache Kafka
Database	MongoDB
Cache/Queue	Redis
Authentication	JWT

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📁 Folder Structure

nihira/
├── frontend/                      # React UI
│   └── src/, components/, pages/
│
├── backend/                       # Node.js Microservices
│   ├── gateway-service/
│   │   └── routes/, controllers/, auth/
│   ├── message-service/
│   │   └── socket/, kafka/, redis/, models/
│   └── notification-service/
│       └── consumers/, utils/
│
├── ai-layer/                      # Chat summarizer, NLP tools
│   └── summarizer/, detectors/, models/
│
├── shared/                        # Shared utilities/constants
│   └── utils/, constants/
│
├── docker-compose.yml
└── README.md

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🔒 Security Highlights

• JWT-based Authentication to secure endpoints and Socket.IO connections.
• Rate Limiting & Input Sanitization (planned).
• Service-to-Service Communication via secure Kafka channels.

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📈 Scalability & Reliability

• Kafka allows decoupling of services for independent scaling.
• Redis Pub/Sub ensures lightweight, real-time state sync.
• Services are containerized and can be deployed across nodes using Docker & AWS.

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🧪 Testing

• ✅ Unit and integration tests (Jest + Supertest)
• ✅ Kafka topic simulation for event reliability
• ✅ Manual tests for real-time socket events

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🧠 Learning Goals

This project was built as part of the CPSC 598 Seminar to demonstrate:

• Real-time backend system design
• Microservices communication patterns
• Kafka-based event streaming
• Production-grade software modularity

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📦 Future Improvements

• User presence/status tracking
• File sharing in chat
• Group messaging and threads
• Admin dashboard for analytics
• Kafka dead-letter queue handling

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🧑‍💻 Author

Mahitha Pasupuleti 🌐 Portfolio | 💼 LinkedIn | 📧 Email Open to internships and full-time roles in Backend Engineering, Distributed Systems, and Real-Time Applications

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📄 License

This project is for educational and portfolio use. Feel free to fork and customize!