InterviewPrep 🎯

A full-stack AI-powered mock interview platform that helps developers practice technical interviews. The application uses Google Gemini AI to generate interview questions and provide intelligent feedback on candidate responses.

✨ Features

• User Authentication: Secure registration and login with OTP email verification
• AI-Powered Interviews: Generate interview questions using Google Gemini AI based on technology and difficulty level
• Real-time Interview Sessions: Interactive interview interface with question-by-question progression
• AI Evaluation: Automated scoring and detailed feedback on interview performance
• Interview History: Track and review all past interview sessions
• User Profiles: Manage and view user profiles with interview statistics
• Dashboard: Comprehensive overview of interview performance and statistics
• Email Notifications: OTP verification and interview updates via email

🛠️ Tech Stack

Backend

• Runtime: Node.js
• Framework: Express.js
• Database: MongoDB with Mongoose
• AI Integration: Google Gemini AI (gemini-2.5-flash)
• Authentication: JWT (JSON Web Tokens) with cookie-based sessions
• Email Service: Nodemailer
• Security: bcrypt for password hashing

Frontend

• Framework: React 19
• Build Tool: Vite
• Styling: Tailwind CSS
• State Management: Redux Toolkit with Redux Persist
• Routing: React Router DOM v7
• HTTP Client: Axios
• Icons: React Icons

📋 Prerequisites

Before you begin, ensure you have the following installed:

• Node.js (v18 or higher)
• npm or yarn
• MongoDB (local instance or MongoDB Atlas account)
• Google Gemini API Key (from Google AI Studio)

🚀 Installation

1. Clone the repository

git clone <repository-url>
cd interviewPrep

2. Backend Setup

cd Backend
npm install

Create a .env file in the Backend directory:

PORT=5000
MONGODB_URL=your_mongodb_connection_string
GEMINI_API_KEY=your_google_gemini_api_key
JWT_SECRET=your_jwt_secret_key
JWT_REFRESH_SECRET=your_jwt_refresh_secret_key
EMAIL_HOST=smtp.gmail.com
EMAIL_PORT=587
EMAIL_USER=your_email@gmail.com
EMAIL_PASS=your_app_specific_password
FRONTEND_URL=http://localhost:5173

3. Frontend Setup

cd Frontend
npm install

Create a .env file in the Frontend directory (if needed):

VITE_API_URL=http://localhost:5000/api/v1

🏃 Running the Application

Development Mode

Backend:

cd Backend
npm run dev

The backend server will start on http://localhost:5000

Frontend:

cd Frontend
npm run dev

The frontend will start on http://localhost:5173

Production Mode

Backend:

cd Backend
npm start

Frontend:

cd Frontend
npm run build
npm run preview

📁 Project Structure

interviewPrep/
├── Backend/
│   ├── app.js                 # Express app configuration
│   ├── index.js               # Server entry point
│   ├── package.json
│   ├── config/
│   │   └── db.js              # MongoDB connection
│   ├── controllers/
│   │   ├── user.controller.js
│   │   ├── interview.controller.js
│   │   └── dashboard.controller.js
│   ├── middelwares/
│   │   └── auth.js            # JWT authentication middleware
│   ├── models/
│   │   ├── User.model.js
│   │   └── Interview.model.js
│   ├── routes/
│   │   ├── user.routes.js
│   │   ├── interview.routes.js
│   │   └── dashboard.routes.js
│   └── utils/
│       ├── gemini.js          # Google Gemini AI integration
│       └── sendEmail.js       # Email service
│
└── Frontend/
    ├── index.html
    ├── package.json
    ├── vite.config.js
    ├── tailwind.config.js
    ├── public/
    └── src/
        ├── App.jsx             # Main app component with routing
        ├── main.jsx            # React entry point
        ├── Layout.jsx          # Layout wrapper
        ├── components/
        │   ├── Header.jsx
        │   ├── Footer.jsx
        │   ├── ProtectedRoute.jsx
        │   ├── ProfileForm.jsx
        │   ├── UserProfileCard.jsx
        │   ├── InterviewHistory.jsx
        │   └── OTPInput.jsx
        ├── pages/
        │   ├── Home.jsx
        │   ├── Login.jsx
        │   ├── Register.jsx
        │   ├── OTPVerification.jsx
        │   ├── Dashboard.jsx
        │   ├── Interview.jsx
        │   ├── InterviewSession.jsx
        │   ├── InterviewResults.jsx
        │   ├── UserProfile.jsx
        │   └── ViewProfile.jsx
        └── store/
            ├── index.js        # Redux store configuration
            └── slices/
                ├── authSlice.js
                ├── interviewSlice.js
                ├── dashboardSlice.js
                └── profileSlice.js

🔌 API Endpoints

User Routes (/api/v1/user)

• POST /register - Register a new user
• POST /verify - Verify email with OTP
• POST /login - User login
• GET /logout - User logout
• POST /resend - Resend OTP
• GET /my-profile - Get logged-in user's profile (Protected)
• PUT /profile - Update user profile (Protected)
• GET /profile/:userId - Get specific user's public profile

Interview Routes (/api/v1/interview)

• POST /start - Start a new interview session (Protected)
• POST /submit/:id - Submit answer for a question (Protected)
• GET /results/:interviewId - Get interview results (Protected)
• GET /history - Get user's interview history (Protected)

Dashboard Routes (/api/v1/dashboard)

• Various dashboard statistics endpoints (Protected)

🎯 Key Features Explained

AI-Powered Question Generation

The application uses Google Gemini AI to generate contextual interview questions based on:

• Technology: e.g., JavaScript, Python, React, Node.js
• Difficulty Level: Beginner, Intermediate, Advanced

Interview Evaluation

After completing an interview, the AI evaluates:

• Overall score (out of 10)
• Detailed feedback on strengths and areas for improvement
• Performance analysis based on difficulty level

Authentication Flow

1. User registers with email
2. OTP sent to email for verification
3. After verification, user can login
4. JWT tokens stored in HTTP-only cookies for security

🔒 Security Features

• Password hashing with bcrypt
• JWT-based authentication
• HTTP-only cookies for token storage
• Protected routes on both frontend and backend
• CORS configuration for secure cross-origin requests

📝 Environment Variables

Backend .env

Variable	Description
PORT	Server port (default: 5000)
MONGODB_URL	MongoDB connection string
GEMINI_API_KEY	Google Gemini API key
JWT_SECRET	Secret for JWT token signing
JWT_REFRESH_SECRET	Secret for refresh token signing
EMAIL_HOST	SMTP server host
EMAIL_PORT	SMTP server port
EMAIL_USER	Email address for sending emails
EMAIL_PASS	App-specific password for email
FRONTEND_URL	Frontend application URL

🧪 Development

Available Scripts

Backend:

• npm start - Start production server
• npm run dev - Start development server with nodemon

Frontend:

• npm run dev - Start development server
• npm run build - Build for production
• npm run preview - Preview production build
• npm run lint - Run ESLint

🤝 Contributing

Contributions are welcome! Please follow these steps:

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

📄 License

This project is licensed under the MIT License.

🙏 Acknowledgments

• Google Gemini AI for interview question generation and evaluation
• React and Vite communities for excellent tooling
• Express.js and MongoDB for robust backend infrastructure

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Note: Make sure to set up all environment variables before running the application. The application requires a valid MongoDB connection and Google Gemini API key to function properly.