🚀 DevNest

DevNest is a scalable backend platform inspired by X (Twitter), built with Node.js, TypeScript, Express, Prisma, PostgreSQL, and Redis.

It follows a clean, layered architecture and focuses on building production-ready social platform features with performance, scalability, and maintainability in mind.

---

🧠 Architecture Overview

DevNest strictly follows this flow:

Routes → Controller → Service → Repository → Database

Why this architecture?

• ✅ Clear separation of concerns
• ✅ Easy to test and refactor
• ✅ Business logic isolated from HTTP & DB layers
• ✅ Scales cleanly as features grow

---

🛠 Tech Stack

• Node.js
• TypeScript
• Express.js
• Prisma ORM
• PostgreSQL
• Redis (Caching & Queues)
• BullMQ (Background Jobs)
• Multer (File Uploads)
• Vite + React (Frontend)
• Tailwind CSS (Styling)
• JWT Authentication (Access & Refresh Tokens)

---

📁 Project Structure

src/
├── modules/          # Feature-based texture (Controller, Service, Routes)
├── middlewares/      # Auth, Rate Limiting, Validation, Error Handling
├── jobs/             # Background workers (Email, Notifications)
├── lib/              # Core utilities (Prisma, Redis, Logger)
├── types/            # Global type definitions
├── app.ts            # Express setup
└── server.ts         # Server entry point

frontend/             # React + Vite application
├── src/
│   ├── api/          # Axios client & API modules
│   ├── components/   # Reusable UI components
│   ├── context/      # React Context (Auth)
│   ├── pages/        # Route pages
│   └── main.tsx      # Frontend entry point

uploads/              # Static file storage (Images)

Each module follows:

module/
├── module.routes.ts
├── module.controller.ts
├── module.service.ts
├── module.repository.ts
└── module.types.ts

---

🔐 Authentication

• JWT-based authentication
• Access & refresh token flow
• Secure route protection via middleware
• Authenticated user attached to req.user

---

⚡ Redis Caching Strategy

Redis is used as a shared caching layer across modules to improve performance and reduce database load.

Where Redis is used

• User profile reads
• Feed responses
• Posts & interactions
• Follow / block checks
• Frequently accessed relational data

Cache Pattern Used

• Read-through caching
• Cache invalidation on write/update/delete
• Fallback to database on cache miss

Example Flow

Request → Redis → Database (if cache miss) → Redis update → Response

Benefits

• 🚀 Faster response times
• 📉 Reduced database queries
• 📈 Better scalability under load

---

🐦 Core Features

👤 Users

• Register & login
• Profile management
• Follow / unfollow users
• Cached profile reads

📝 Posts

• Create posts
• Fetch posts efficiently
• Cached post lists

❤️ Likes

• Like / unlike posts
• Prevent duplicate likes
• Cache-aware invalidation

💬 Comments

• Comment on posts
• Delete own comments

🚫 Blocking (X-like Behavior)

• Block users

• Unblock users

• View blocked users list

• Blocking removes follow relationships

• Blocked users cannot:

  • follow
  • like
  • comment
  • view feed content

📰 Feed

• Feed based on follow relationships
• Block-aware feed filtering
• Redis-cached feed responses

📨 Background Jobs & Notifications

• BullMQ + Redis based job queue
• Asynchronous email sending (Welcome emails)
• Notification generation (Likes, Follows)

🛡️ Security & Performance

• Rate Limiting: Redis-based sliding window limiter protected endpoints.
• JWT Auth: Secure access/refresh token rotation.
• Helmet & CORS: Enhanced security headers.

🖼️ Media Management

• Image uploads via Multer
• Static file serving for user avatars and post images

---

🧱 Database Design (Prisma)

Key models:

• User
• Post
• Follow
• BlockedUser
• Like
• Comment

Designed with:

• Unique constraints
• Indexes for performance
• Cascade deletes
• Proper relational modeling

---

⚙️ Setup & Installation

1️⃣ Clone the repository

git clone https://github.com/johnvesslyalti/dev-nest.git
cd dev-nest

2️⃣ Install dependencies

npm install

3️⃣ Setup environment variables

Create a .env file:

DATABASE_URL=postgresql://user:password@localhost:5432/devnest
REDIS_URL=redis://localhost:6379
JWT_SECRET=your_jwt_secret
REFRESH_TOKEN_SECRET=your_refresh_secret

4️⃣ Run Prisma

npx prisma generate
npx prisma migrate dev

5️⃣ Start Redis

redis-server

6️⃣ Start the Backend

npm run dev

7️⃣ Start the Frontend

Open a new terminal:

cd frontend
npm install
npm run dev

The app will be available at http://localhost:5173.

---

🧪 Development Principles

• ❌ No Prisma calls in controllers
• ❌ No HTTP logic in services
• ❌ No business logic in repositories
• ✅ Repositories handle DB access
• ✅ Services enforce business rules
• ✅ Redis caching handled consistently per module

---

🚧 Future Enhancements

• WebSocket-based real-time updates (Socket.io)
• Retweets / reposts
• Hashtags & trending topics
• Direct messaging
• API documentation (Swagger / OpenAPI)

---

👨‍💻 Author

Johnvessly Alti Backend-focused Software Engineer Building scalable systems with clean architecture.

---

⭐ Contributing

Pull requests are welcome. Please open an issue before making major changes.

---

📄 License

MIT License