Skill Badge Platform Backend

A comprehensive backend system for skill verification, badge management, and professional development tracking with AI-powered features and OAuth integration.

| 🚀 Live Application | 🟢 Up | Visit Frontend App | | 📡 Backend API | 🟢 Up | Base API URL | | 💻 Frontend Repo | 📂 Code | View Frontend Source |

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📋 Table of Contents

• Overview
• System Architecture
• Features
• Tech Stack
• Project Structure
• Prerequisites
• Installation
• Configuration
• Getting Started
• Running the Application
• Database Seeding
• API Documentation
• Development
• Testing
• Deployment
• Contributing
• License
• Support

---

🎯 Overview

The Skill Badge Platform Backend is a robust, scalable Node.js application built with TypeScript that powers a comprehensive skill verification and badge management system. It enables organizations and individuals to create, manage, and verify professional skills through digital badges, with features including AI-powered content generation, real-time discussions, OAuth authentication, and cloud-based media management.

Key Capabilities

• Multi-provider OAuth Authentication (Google, GitHub)
• AI-Powered Content Generation using OpenRouter integration
• Real-time Discussion Forums for skill-based communities
• Cloud Media Management via Cloudinary
• Email Notifications for user engagement
• Role-Based Access Control (RBAC)
• Badge Verification System with cryptographic proof
• RESTful API with comprehensive endpoints

---

🏗️ System Architecture

The platform follows a modular, layered architecture designed for scalability and maintainability:

┌─────────────────────────────────────────────────┐
│           Client Applications (Web/Mobile)       │
└───────────────────┬─────────────────────────────┘
                    │
                    ▼
┌─────────────────────────────────────────────────┐
│         Express.js REST API Layer               │
│  (Routes → Controllers → Services → Models)     │
└───────────────────┬─────────────────────────────┘
                    │
        ┌───────────┼───────────┐
        ▼           ▼           ▼
   ┌────────┐  ┌────────┐  ┌─────────┐
   │MongoDB │  │Cloudinary│ │OpenRouter│
   │Database│  │ (Media) │  │  (AI)   │
   └────────┘  └────────┘  └─────────┘

Design Principles

• Separation of Concerns: Clear boundaries between routes, controllers, services, and data models
• Dependency Injection: Loose coupling between components
• Error Handling: Centralized error management with custom error classes
• Security First: JWT authentication, input validation, and sanitization
• Scalability: Stateless design supporting horizontal scaling

---

✨ Features

Authentication & Authorization

• 🔐 JWT-based authentication with refresh tokens
• 🌐 OAuth 2.0 integration (Google, GitHub)
• 👥 Role-based access control (Admin, Instructor, Student)
• 📧 Email verification and password reset
• 🔄 Token refresh mechanism

Challenges & Programming

• 💻 Create and manage coding challenges
• 🔧 Support for multiple programming languages (Python, JavaScript, Java, C++, etc.)
• ⚡ Real-time code execution using Piston API
• 🎯 Challenge categorization by difficulty (EASY, MEDIUM, HARD)
• 🏆 Submission tracking and validation
• 💡 AI-powered hint generation
• 🎮 Random unsolved challenge suggestions

Daily Challenge System

• 📅 Daily randomized challenge selection
• 🎁 Daily challenge motivation system
• ⚙️ Lazy-loading daily challenge creation
• 🔄 One challenge per day rotation

AI-Powered Interview System

• 🤖 Multi-stream technical interview simulation (Frontend, Backend, Full-stack)
• 🎓 Difficulty levels (Beginner, Intermediate, Advanced)
• 💬 AI-powered conversational interviews with Gemini
• 📊 10-question per interview with final feedback report
• 🎯 Interview status tracking (ACTIVE, COMPLETED)
• ⏱️ Message history and conversation logging
• 📋 Automated scoring system (0-100)

Coding Contests

• 🏅 Multi-problem contest management
• ⏱️ Time-limited contest events
• 🎯 Variable point distribution (10, 20, 30, 40 points)
• 👥 Participant tracking and leaderboards
• 📊 Contest-based competitive programming

Discussion & Collaboration

• 💬 Real-time discussion forums per challenge/badge
• 👥 Comment and reply functionality
• 🔔 Socket.io real-time notifications
• 📝 Post management and moderation
• 👁️ View tracking per post (unique users and guests)
• 📊 View analytics with auto-expiry (24-hour)

Badge Management

• 🏅 Create and manage skill badges
• ✅ Badge verification system
• 📊 Badge analytics and tracking
• 🎨 Custom badge designs with Cloudinary
• 📜 Badge issuance history
• 🎖️ Badge-specific discussion forums

Media Management

• ☁️ Cloud storage integration (Cloudinary)
• 🖼️ Image upload and optimization
• 📦 File organization and retrieval
• 🔒 Secure media access control

Admin Dashboard & Analytics

• 👨‍💼 Comprehensive user management
• 📊 Platform analytics and insights
• 🛠️ Challenge creation and management
• 🎯 Contest management and monitoring
• 📋 Content moderation tools
• 🔧 System configuration and settings

---

🛠️ Tech Stack

Core Technologies

• Runtime: Node.js (≥18.0.0)
• Language: TypeScript (5.0+)
• Framework: Express.js (5.0+)
• Database: MongoDB (v5.0+) with Mongoose ODM

Authentication & Security

• JWT: JSON Web Tokens for stateless authentication
• Passport.js: OAuth strategies (Google, GitHub)
• bcryptjs: Password hashing and security

Real-time Communication

• Socket.io: Real-time bidirectional communication for discussions
• HTTP: RESTful API endpoints

Code Execution & AI

• Piston API: Remote code execution for 50+ programming languages
• Google Gemini AI: Conversational AI for technical interviews
• OpenRouter: LLM integration for AI-powered features
• OpenAI: AI content generation

Cloud Services

• Cloudinary: Media storage, optimization, and transformation
• SMTP: Email delivery service (Gmail, SendGrid compatible)

File Management

• Multer: Multipart form data handling for file uploads
• Streamifier: Stream-based file conversion

Development & DevOps Tools

• ts-node: TypeScript execution without compilation
• ts-node-dev: Development server with auto-reload
• dotenv: Environment configuration management
• TypeScript: Strict type checking and modern JavaScript features

Libraries & Utilities

• Mongoose: MongoDB object modeling
• Axios: HTTP client
• Nodemailer: Email sending
• jsonwebtoken: JWT creation and verification
• cors: Cross-Origin Resource Sharing
• express-validator: Input validation

---

📁 Project Structure

skill-badge-platform-backend/
├── src/
│   ├── config/                          # Configuration files
│   │   ├── cloudinary.ts                # Cloudinary setup
│   │   ├── passport.ts                  # OAuth strategies
│   │   └── seeds/
│   │       └── badgeManifest.ts         # Badge seed data
│   │
│   ├── controllers/                     # Request handlers
│   │   ├── admin/                       # Admin-specific controllers
│   │   │   ├── admin.analytics.controller.ts
│   │   │   ├── admin.Challenge.controller.ts
│   │   │   ├── admin.contest.controller.ts
│   │   │   ├── admin.dashboard.controller.ts
│   │   │   ├── admin.setting.controller.ts
│   │   │   └── admin.user.controller.ts
│   │   ├── auth.controller.ts           # Authentication logic
│   │   ├── challenge.controller.ts      # Challenge CRUD & logic
│   │   ├── daily.challenge.controller.ts # Daily challenge logic
│   │   ├── discuss.controller.ts        # Discussion/posts logic
│   │   ├── interview.controller.ts      # Interview system logic
│   │   ├── submission.controller.ts     # Code submission & execution
│   │   └── user.controller.ts           # User profile management
│   │
│   ├── middleware/                      # Custom middleware
│   │   ├── auth.ts                      # JWT authentication middleware
│   │   ├── role.ts                      # Role-based access control
│   │   └── upload.ts                    # Multer file upload handling
│   │
│   ├── models/                          # Mongoose schemas
│   │   ├── badge.model.ts               # Badge schema
│   │   ├── challenge.model.ts           # Challenge schema
│   │   ├── comment.model.ts             # Comment schema
│   │   ├── contest.model.ts             # Contest schema
│   │   ├── dailyChallenge.model.ts      # Daily challenge tracking
│   │   ├── interview.model.ts           # Interview session schema
│   │   ├── post.model.ts                # Discussion post schema
│   │   ├── submission.model.ts          # Code submission schema
│   │   ├── user.model.ts                # User schema
│   │   └── view.model.ts                # Post view tracking schema
│   │
│   ├── routes/                          # API route definitions
│   │   ├── admin.routes.ts              # Admin routes
│   │   ├── auth.ts                      # Authentication routes
│   │   ├── challenge.ts                 # Challenge routes
│   │   ├── discuss.ts                   # Discussion routes
│   │   ├── interview.ts                 # Interview routes
│   │   └── user.ts                      # User routes
│   │
│   ├── scripts/                         # Utility scripts
│   │   ├── seedAdmin.ts                 # Admin user seeding
│   │   └── seedBadges.ts                # Badge seeding
│   │
│   ├── service/                         # Business logic layer
│   │   ├── ai.service.ts                # AI integration service
│   │   └── badge.service.ts             # Badge management service
│   │
│   ├── utils/                           # Utility functions
│   │   ├── ai.ts                        # AI prompt templates
│   │   ├── cloudinary.ts                # Cloudinary utilities
│   │   ├── openrouter.ts                # OpenRouter API wrapper
│   │   ├── piston.ts                    # Piston code execution API
│   │   ├── SendMailUtil.ts              # Email utility
│   │   └── tokens.ts                    # JWT token utilities
│   │
│   └── index.ts                         # Application entry point
│
├── dist/                                # Compiled JavaScript (generated)
├── node_modules/                        # Dependencies
├── package.json                         # Project metadata & dependencies
├── tsconfig.json                        # TypeScript configuration
├── test.js                              # Test file
└── README.md                            # This file

📋 Prerequisites

Before you begin, ensure you have the following installed:

• Node.js (v18.0.0 or higher)
• npm (v9.0.0 or higher) or yarn
• MongoDB (v5.0 or higher)
  • Local installation OR MongoDB Atlas account
• Git for version control

External Service Accounts

You'll need accounts and API keys for:

1. Google OAuth: Google Cloud Console
2. GitHub OAuth: GitHub Developer Settings
3. Cloudinary: Cloudinary Console
4. OpenRouter: OpenRouter Dashboard
5. SMTP Service: Gmail, SendGrid, or similar

---

🚀 Installation

1. Clone the Repository

git clone https://github.com/Sachintha-Prabashana/skillbadge-backend.git
cd skillbadge-backend

2. Install Dependencies

npm install

3. Set Up Environment Variables

Create a .env file in the root directory:

cp .env.example .env

Edit the .env file with your configuration (see Configuration section below).

---

⚙️ Configuration

Environment Variables

Create a .env file with the following variables:

Server Configuration

# Server Port
PORT=5000

# Node Environment (development | production | test)
NODE_ENV=development

Database Configuration

# MongoDB Connection URI
MONGO_URI=mongodb://localhost:27017/skill-badge-platform
# For MongoDB Atlas:
# MONGO_URI=mongodb+srv://<username>:<password>@cluster.mongodb.net/<dbname>?retryWrites=true&w=majority

JWT Configuration

# JWT Secret Keys (Generate strong random strings)
JWT_SECRET=your-super-secure-jwt-secret-key-min-32-chars
JWT_REFRESH_SECRET=your-super-secure-refresh-token-secret-key

# Token Expiration
JWT_EXPIRE=7d
JWT_REFRESH_EXPIRE=30d

Google OAuth Configuration

# Google OAuth 2.0 Credentials
GOOGLE_CLIENT_ID=your-google-client-id.apps.googleusercontent.com
GOOGLE_CLIENT_SECRET=your-google-client-secret
GOOGLE_CALLBACK_URL=http://localhost:5000/api/v1/auth/google/callback

Setup Instructions for Google OAuth:

1. Go to Google Cloud Console
2. Create a new project or select existing
3. Enable Google+ API
4. Create OAuth 2.0 credentials
5. Add authorized redirect URIs

GitHub OAuth Configuration

# GitHub OAuth App Credentials
GITHUB_CLIENT_ID=your-github-client-id
GITHUB_CLIENT_SECRET=your-github-client-secret
GITHUB_CALLBACK_URL=http://localhost:5000/api/v1/auth/github/callback

Setup Instructions for GitHub OAuth:

1. Go to GitHub Developer Settings
2. Create a new OAuth App
3. Set Authorization callback URL
4. Copy Client ID and generate Client Secret

Cloudinary Configuration

# Cloudinary Cloud Storage
CLOUDINARY_CLOUD_NAME=your-cloudinary-cloud-name
CLOUDINARY_API_KEY=your-cloudinary-api-key
CLOUDINARY_API_SECRET=your-cloudinary-api-secret

Setup Instructions for Cloudinary:

1. Sign up at Cloudinary
2. Navigate to Dashboard
3. Copy Cloud name, API Key, and API Secret

Email Configuration (SMTP)

# SMTP Server Configuration
SMTP_HOST=smtp.gmail.com
SMTP_PORT=587
SMTP_EMAIL=your-email@gmail.com
SMTP_PASSWORD=your-app-specific-password

# Email From Details
FROM_NAME=Skill Badge Platform
FROM_EMAIL=noreply@skillbadge.com

Setup Instructions for Gmail SMTP:

1. Enable 2-Factor Authentication on your Google Account
2. Generate an App Password: Google App Passwords
3. Use the generated password in SMTP_PASSWORD

AI Configuration (OpenRouter)

# OpenRouter API for AI Features
OPENROUTER_API_KEY=sk-or-v1-your-openrouter-api-key

Setup Instructions for OpenRouter:

1. Sign up at OpenRouter
2. Navigate to API Keys section
3. Create a new API key
4. Copy the key to your .env file

Optional Configuration

# File Upload Limits
MAX_FILE_SIZE=5242880  # 5MB in bytes

# Rate Limiting
RATE_LIMIT_WINDOW=15   # minutes
RATE_LIMIT_MAX=100     # requests per window

# CORS Origins (comma-separated)
CORS_ORIGIN=http://localhost:3000,http://localhost:3001

Security Best Practices

• Never commit .env files to version control
• Use strong, unique secrets for JWT tokens (minimum 32 characters)
• Rotate API keys regularly
• Use environment-specific .env files (.env.development, .env.production)
• Store production secrets in secure vaults (AWS Secrets Manager, HashiCorp Vault)

---

🚀 Getting Started

Quick Setup (5 minutes)

1. Clone and install dependencies:

git clone https://github.com/Sachintha-Prabashana/skillbadge-backend.git
cd skillbadge-backend
npm install

2. Create .env file with essential variables:

PORT=5000
NODE_ENV=development
MONGO_URI=mongodb://localhost:27017/skill-badge-platform
JWT_SECRET=your-super-secret-jwt-key-min-32-chars
JWT_REFRESH_SECRET=your-super-secret-refresh-key
GOOGLE_CLIENT_ID=your-google-client-id
GOOGLE_CLIENT_SECRET=your-google-client-secret
GOOGLE_CALLBACK_URL=http://localhost:5000/api/v1/auth/google/callback
CLOUDINARY_CLOUD_NAME=your-cloud-name
CLOUDINARY_API_KEY=your-api-key
CLOUDINARY_API_SECRET=your-api-secret
OPENROUTER_API_KEY=your-openrouter-api-key
SMTP_HOST=smtp.gmail.com
SMTP_PORT=587
SMTP_EMAIL=your-email@gmail.com
SMTP_PASSWORD=your-app-password

3. Start the development server:

npm run dev

4. Create admin user:

npm run seed:admin

5. Test the API:

curl http://localhost:5000/api/v1/challenges

Minimum Requirements for Basic Testing

You need at minimum:

• MongoDB (local or Atlas)
• Node.js 18+
• One OAuth provider (Google or GitHub) OR local JWT testing
• Optional: Cloudinary for media features

For full features:

• Google/GitHub OAuth accounts
• Cloudinary account
• OpenRouter API key (for AI interviews)
• SMTP email service

---

🏃‍♂️ Running the Application

Development Mode

Run with hot-reload enabled:

npm run dev

The server will start on http://localhost:5000 (or your configured PORT).

Production Mode

1. Build the TypeScript code:

npm run build

2. Start the production server:

npm start

Available Scripts

# Development with auto-reload
npm run dev

# Build TypeScript to JavaScript
npm run build

# Start production server
npm start

# Run tests
npm test

# Lint code
npm run lint

# Format code
npm run format

# Seed admin user
npm run seed:admin

---

🌱 Database Seeding

Create Admin User

To create an initial admin user for the platform:

npm run seed:admin

Default Admin Credentials:

• Email: admin@skillbadge.com
• Password: Admin@123

⚠️ Important: Change the default password immediately after first login in production environments.

Custom Seeding

You can modify the src/scripts/seedAdmin.ts file to customize the admin user details.

---

📡 API Documentation

Base URL

https://controlled-karina-spsolutions-ea693d09.koyeb.app/api/v1

Authentication Endpoints

Login / Register

POST /auth/login
POST /auth/register
POST /auth/logout
POST /auth/refresh-token

OAuth

GET /auth/google
GET /auth/google/callback
GET /auth/github
GET /auth/github/callback

Challenge Endpoints

Get All Challenges

GET /challenges
Headers: Authorization: Bearer <token>

Response:

{
  "challenges": [
    {
      "_id": "123abc",
      "title": "Two Sum",
      "difficulty": "EASY",
      "description": "Find two numbers that add up to target",
      "languages": ["python", "javascript"],
      "testCases": [...],
      "solved": true
    }
  ],
  "totalPages": 5,
  "currentPage": 1
}

Get Challenge by ID

GET /challenges/:id
Headers: Authorization: Bearer <token>

Submit Challenge Solution

POST /challenges/submit
Headers: Authorization: Bearer <token>
Content-Type: application/json

{
  "challengeId": "123abc",
  "code": "def twoSum(nums, target):\n  ...",
  "language": "python"
}

Run Code (Piston Execution)

POST /challenges/run
Headers: Authorization: Bearer <token>
Content-Type: application/json

{
  "challengeId": "123abc",
  "code": "print('Hello')",
  "language": "python"
}

Response:

{
  "results": [
    {
      "output": "Hello",
      "expected": "Hello",
      "passed": true
    }
  ],
  "allPassed": true
}

Get Challenge Hint

POST /challenges/:id/hint
Headers: Authorization: Bearer <token>

Get Random Unsolved Challenge

GET /challenges/random
Headers: Authorization: Bearer <token>

Daily Challenge Endpoints

Get Today's Daily Challenge ID

GET /challenges/daily/id
Headers: Authorization: Bearer <token>

Response:

{
  "challengeId": "65a4f8c9d1e2f3g4h5i6j7k8"
}

Interview Endpoints

Start Technical Interview

POST /interview/start
Headers: Authorization: Bearer <token>
Content-Type: application/json

{
  "stream": "Frontend",
  "difficulty": "Intermediate"
}

Response:

{
  "interviewId": "int_123abc",
  "stream": "Frontend",
  "difficulty": "Intermediate",
  "message": "What is the Virtual DOM and how does it work?"
}

Chat Interview (Answer Question)

POST /interview/chat
Headers: Authorization: Bearer <token>
Content-Type: application/json

{
  "interviewId": "int_123abc",
  "userAnswer": "The Virtual DOM is a lightweight JavaScript representation of the real DOM..."
}

Response:

{
  "message": "Great explanation! Now, can you explain React hooks?",
  "questionCount": 2,
  "isCompleted": false
}

Final Response (10th question):

{
  "message": "Interview Completed.\n\nFinal Feedback Report:\nScore: 85/100\nStrengths: Good understanding of React fundamentals\nWeaknesses: Need more practice with advanced patterns",
  "questionCount": 10,
  "isCompleted": true
}

Discussion Endpoints

Get All Posts

GET /discuss
Headers: Authorization: Bearer <token>

Create Post

POST /discuss
Headers: Authorization: Bearer <token>
Content-Type: application/json

{
  "title": "Need help with recursion",
  "content": "I'm struggling with implementing binary search...",
  "challengeId": "123abc",
  "tags": ["recursion", "arrays"]
}

Add Comment

POST /discuss/:postId/comment
Headers: Authorization: Bearer <token>
Content-Type: application/json

{
  "content": "You can use two pointers approach..."
}

Track Post View

POST /discuss/:postId/view
Headers: Authorization: Bearer <token>

Real-time Socket.io Events:

// Client-side
socket.emit('join_post', postId);
socket.on('new_comment', (comment) => {
  // Handle new comment
});

User Endpoints

Get User Profile

GET /users/profile
Headers: Authorization: Bearer <token>

Update User Profile

PUT /users/profile
Headers: Authorization: Bearer <token>
Content-Type: application/json

{
  "firstName": "John",
  "lastName": "Doe",
  "bio": "Full-stack developer"
}

Get User Statistics

GET /users/stats
Headers: Authorization: Bearer <token>

Response:

{
  "challengesSolved": 25,
  "badges": 5,
  "interviewsCompleted": 3,
  "totalPoints": 450,
  "level": "Gold"
}

Admin Endpoints

User Management

GET /admin/users                    # List all users
GET /admin/users/:id               # Get user details
PUT /admin/users/:id               # Update user
DELETE /admin/users/:id            # Delete user

Challenge Management

POST /admin/challenges             # Create challenge
PUT /admin/challenges/:id          # Update challenge
DELETE /admin/challenges/:id       # Delete challenge

Contest Management

POST /admin/contests               # Create contest
GET /admin/contests                # List contests
PUT /admin/contests/:id            # Update contest
GET /admin/contests/:id/stats      # Contest statistics

Analytics

GET /admin/analytics/dashboard     # Platform overview
GET /admin/analytics/users         # User statistics
GET /admin/analytics/challenges    # Challenge statistics
GET /admin/analytics/contests      # Contest statistics

---

💻 Development

Code Standards

• Language: TypeScript with strict type checking
• Style: Follow Express.js and Node.js best practices
• Patterns: MVC architecture with controllers, services, and models
• Error Handling: Centralized error handling middleware
• Validation: Input validation on all endpoints

Development Workflow

1. Create a feature branch:

git checkout -b feature/your-feature-name

2. Make your changes:

   • Write clean, documented code
   • Follow TypeScript conventions
   • Use meaningful variable and function names

3. Test your changes:

npm run dev
# Test endpoints with Postman or curl

4. Build before commit:

npm run build

5. Commit with descriptive messages:

git commit -m "feat: add new interview feature"
git push origin feature/your-feature-name

Useful Development Commands

# Development with auto-reload
npm run dev

# Build TypeScript
npm run build

# Seed database
npm run seed:admin

# Check for TypeScript errors
npx tsc --noEmit

File Upload Guide

File uploads are handled through Cloudinary. The upload.ts middleware manages:

• File validation
• Size restrictions
• Format checking
• Security scanning

Real-time Features

The platform uses Socket.io for:

• Real-time discussion comments
• Live notification delivery
• Post view count updates

Socket rooms are managed by Post ID for targeted updates.

---

🧪 Testing

Manual Testing

Use tools like Postman or Insomnia to test API endpoints.

Unit Testing

npm test

Integration Testing

Test complete workflows:

• User registration → Login → Challenge submission
• Interview creation → Answer questions → Get feedback
• Discussion post → Comments → Notifications

---

🚀 Deployment

Deployment Platforms

The backend can be deployed to:

• Koyeb (Current deployment)
• Heroku
• Railway
• Render
• AWS Elastic Beanstalk
• DigitalOcean App Platform

Pre-deployment Checklist

• Update all environment variables
• Run npm run build successfully
• Test all OAuth callbacks are correct
• Verify Cloudinary credentials
• Check MongoDB Atlas connection
• Update CORS origins
• Set NODE_ENV=production
• Review security headers
• Test error handling

Environment-Specific Configuration

Development (.env.development):

NODE_ENV=development
DEBUG=true

Production (.env.production):

NODE_ENV=production
DEBUG=false

---

🤝 Contributing

We welcome contributions! Please follow these steps:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/AmazingFeature)
3. Commit changes (git commit -m 'Add AmazingFeature')
4. Push to branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

Contribution Guidelines

• Write clear commit messages
• Update documentation for new features
• Test your changes thoroughly
• Follow existing code style
• Add comments for complex logic

---

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

---

---

💬 Support

Get Help

• 📧 Email: sachinthaprabhashana2003@gmail.com
• 🐙 GitHub Issues: Report a bug
• 📚 Documentation: Check README and API docs above
• 💻 Frontend Repo: skillbadge-frontend

Common Issues

MongoDB Connection Error:

• Verify MONGO_URI is correct
• Check MongoDB service is running
• Ensure network access is allowed (Atlas)

OAuth Not Working:

• Verify callback URLs match exactly
• Check client ID and secret are correct
• Clear browser cache and cookies

Email Not Sending:

• Enable "Less secure apps" (Gmail) or use App Password
• Verify SMTP credentials
• Check email quota not exceeded

Code Execution Errors:

• Verify Piston API is accessible
• Check language is supported
• Test with simple code first

---

🙏 Acknowledgments

Technologies & Services

• Express.js - Web application framework
• MongoDB - NoSQL database
• Mongoose - MongoDB object modeling
• Socket.io - Real-time communication
• Passport.js - Authentication middleware
• Cloudinary - Cloud media management
• Google Gemini - AI/ML capabilities
• OpenRouter - LLM API aggregation
• Piston - Code execution engine
• TypeScript - Type-safe JavaScript

Contributors

Special thanks to all contributors who have helped improve this project.

Inspiration

Built with inspiration from modern coding platforms like:

• LeetCode
• HackerRank
• CodeSignal
• InterviewBit

Community

• Express.js community
• MongoDB team
• Node.js developers worldwide
• Open-source contributors

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📞 Contact & Social

• 📧 Email: sachinthaprabhashana2003@gmail.com
• 🐙 GitHub: @Sachintha-Prabashana
• 🌐 Portfolio: Visit My Site

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📝 Changelog

Version 1.0.0 (Current)

Features:

• ✅ Authentication (JWT + OAuth)
• ✅ Challenge management with code execution
• ✅ Daily challenge system
• ✅ AI-powered technical interviews
• ✅ Coding contests
• ✅ Real-time discussions
• ✅ Badge system
• ✅ Admin dashboard with analytics
• ✅ Media management (Cloudinary)
• ✅ Socket.io real-time updates

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