PrepPilot - AI-Powered Interview Preparation Platform

Your ultimate companion for crushing technical interviews with AI-powered questions, real-time feedback, and comprehensive preparation tools.

🌐 Live Demo • 📖 Documentation • 🐛 Report Bug • 💡 Request Feature

🚀 About PrepPilot

PrepPilot is a comprehensive full-stack web application designed to transform your interview preparation journey. Leveraging cutting-edge AI technology and an intuitive interface, PrepPilot generates role-specific interview questions, provides detailed explanations, and helps you track your progress in real-time.

Whether you're preparing for your dream job or sharpening your technical skills, PrepPilot provides all the tools you need to succeed.

✨ Key Features

Feature	Description
🤖 AI-Powered Question Generation	Generate unlimited role-specific interview questions using Google's Gemini AI
📚 Curated Question Banks	Access DSA sheets, aptitude questions, and problem-solving challenges
💻 Built-in Code Compiler	Write, test, and execute code directly in the browser with Monaco Editor
🎯 Skill Assessment	Evaluate your technical proficiency with interactive skill tests
📖 Reference Books Library	Access a comprehensive collection of interview preparation books
📝 Resume Builder	Create professional resumes with customizable templates
🏆 Interview Experiences	Read and share real interview experiences from the community
💡 Project Ideas	Explore curated project ideas to enhance your portfolio
🔗 Open Source Resources	Contribute and learn from open-source projects
📊 Progress Dashboard	Track your preparation metrics and identify weak areas
🔐 Secure Authentication	JWT-based authentication with encrypted passwords
📱 Fully Responsive	Seamless experience across desktop, tablet, and mobile devices
🎨 Modern Dark Mode	Beautiful UI with theme toggle for comfortable viewing
⚡ Real-time Feedback	Instant AI-powered explanations and answer evaluations

🛠️ Technology Stack

Frontend Architecture

React 18 (Hooks & Functional Components)
├── Vite (Lightning-fast build tool)
├── Tailwind CSS (Utility-first styling)
├── React Router DOM (Client-side routing)
├── Framer Motion (Smooth animations)
├── Monaco Editor (Advanced code editing)
├── React Markdown (Rich content rendering)
└── Axios (HTTP client for API calls)

Backend Architecture

Node.js + Express.js
├── MongoDB + Mongoose (Data persistence)
├── JWT & Bcryptjs (Security & authentication)
├── Google Gemini API (AI intelligence)
├── Multer (File uploads)
├── PDF-Parse (Document processing)
├── Express Rate Limit (API protection)
└── Joi (Input validation)

Development & DevOps

ESLint          Code quality & linting
Git             Version control
Nodemon         Auto-reload during development

📦 Complete Dependency Stack

Frontend Dependencies: React 18 • Vite • Tailwind CSS • React Router • Axios • Framer Motion • Monaco Editor • Lucide React • React Icons • React Markdown • React Syntax Highlighter • React Hot Toast • React Split • Moment.js

Backend Dependencies: Express.js • MongoDB • Mongoose • JWT • Bcryptjs • Google Generative AI • Axios • Multer • PDF-Parse • Joi • CORS • Express Rate Limit • Dotenv

⚡ Quick Start Guide

Prerequisites

Before getting started, ensure you have the following installed:

Node.js (v16 or higher) - Download
npm or yarn (v7 or higher)
MongoDB instance (Local or MongoDB Atlas - Free tier available)
Google Gemini API Key - Get it free at Google AI Studio

📥 Installation Steps

1️⃣ Clone the Repository

git clone https://github.com/yourusername/PrepPilot.git
cd PrepPilot

2️⃣ Backend Setup

cd backend
npm install

3️⃣ Frontend Setup

cd ../frontend
npm install

4️⃣ Environment Configuration

Create a .env file in the backend/ directory with the following variables:

# MongoDB Configuration
MONGO_URI=mongodb+srv://username:password@cluster.mongodb.net/preppilot

# JWT Secret (generate a strong random string)
JWT_SECRET=your_super_secret_jwt_key_here_generate_a_strong_one

# Google Gemini API
GEMINI_API_KEY=your_gemini_api_key_from_ai_studio
GEMINI_MODEL=gemini-1.5-flash

# Server Configuration
PORT=8000
NODE_ENV=development

# Frontend Origin (for CORS)
FRONTEND_ORIGIN=http://localhost:5173

# Optional: Additional configurations
RATE_LIMIT_WINDOW_MS=15000000
RATE_LIMIT_MAX_REQUESTS=100

5️⃣ Start Development Servers

Terminal 1 - Backend:

cd backend
npm run dev
# Server runs on http://localhost:8000

Terminal 2 - Frontend:

cd frontend
npm run dev
# Frontend runs on http://localhost:5173

6️⃣ Access the Application

Open your browser and navigate to:

http://localhost:5173

🐳 Docker Setup (Optional)

# Build and run with Docker Compose
docker-compose up --build

📁 Project Structure

PrepPilot/
│
├── 📂 backend/                        # Express.js REST API Server
│   ├── 📂 config/                    # Database & environment configuration
│   ├── 📂 controllers/               # Business logic & request handlers
│   │   ├── aiController.js           # AI/Gemini API integration
│   │   ├── authController.js         # Authentication logic
│   │   ├── questionController.js     # Question management
│   │   ├── resumeController.js       # Resume operations
│   │   ├── sessionController.js      # Session management
│   │   └── userSheetProgressController.js # Progress tracking
│   │
│   ├── 📂 middlewares/               # Express middlewares
│   │   ├── authMiddleware.js         # JWT verification
│   │   ├── rateLimiter.js            # API rate limiting
│   │   ├── uploadMiddleware.js       # File upload handling
│   │   ├── sanitizeAiPrompt.js       # Input sanitization
│   │   └── validateAiPrompt.js       # Prompt validation
│   │
│   ├── 📂 models/                    # MongoDB Mongoose schemas
│   │   ├── User.js                   # User profile & credentials
│   │   ├── Question.js               # Interview questions
│   │   ├── Resume.js                 # Resume documents
│   │   ├── Session.js                # Practice sessions
│   │   ├── Sheet.js                  # Question sheets (DSA, etc.)
│   │   ├── Book.js                   # Reference books
│   │   └── UserSheetProgress.js      # User progress tracking
│   │
│   ├── 📂 routes/                    # API endpoints
│   │   ├── authRoutes.js             # Auth endpoints
│   │   ├── aiRoutes.js               # AI generation endpoints
│   │   ├── questionRoutes.js         # Question endpoints
│   │   ├── resumeRoutes.js           # Resume endpoints
│   │   ├── sessionRoutes.js          # Session endpoints
│   │   ├── booksRoutes.js            # Books endpoints
│   │   ├── AptitudeQuestions.js      # Aptitude test endpoints
│   │   ├── sheetJsonUpload.js        # Sheet upload
│   │   └── userSheetProgressRoutes.js# Progress endpoints
│   │
│   ├── 📂 utils/                     # Utility functions
│   │   └── prompts.js                # AI prompt templates
│   │
│   ├── 📂 validation/                # Input validation schemas
│   │   └── aiPromptSchema.js         # Joi validation schemas
│   │
│   ├── 📂 scripts/                   # Utility scripts
│   │   ├── importBooks.js            # Import books to DB
│   │   ├── exportBooks.js            # Export books from DB
│   │   └── uploadSheets.js           # Upload question sheets
│   │
│   ├── 📂 sheets/                    # JSON question sheets
│   │   ├── Arrays.json
│   │   ├── gfg-must-know-dsa.json
│   │   ├── neetcode-150.json
│   │   ├── striver-sde-sheet.json
│   │   └── love-babbar-dsa-sheet.json
│   │
│   ├── 📂 uploads/                   # User-uploaded files storage
│   ├── server.js                     # Express server entry point
│   ├── package.json
│   └── .env.example
│
├── 📂 frontend/                       # React + Vite Frontend Application
│   ├── 📂 public/                    # Static assets
│   ├── 📂 src/
│   │   ├── 📂 components/            # Reusable UI components
│   │   │   ├── AIHelper.jsx          # AI question generator
│   │   │   ├── Compiler.jsx          # Code editor & executor
│   │   │   ├── SkillAssessment.jsx   # Skill tests
│   │   │   ├── SheetList.jsx         # Question sheets list
│   │   │   ├── SheetDetailsPage.jsx  # Sheet details view
│   │   │   ├── ThemeToggle.jsx       # Dark/Light mode
│   │   │   ├── Drawer.jsx            # Navigation drawer
│   │   │   │
│   │   │   ├── 📂 Cards/             # Card components
│   │   │   │   ├── QuestionCard.jsx
│   │   │   │   ├── AptitudeQuestionCard.jsx
│   │   │   │   ├── TopicCard.jsx
│   │   │   │   └── SummaryCard.jsx
│   │   │   │
│   │   │   ├── 📂 Inputs/            # Form input components
│   │   │   │   ├── Input.jsx
│   │   │   │   └── ProfilePhotoSelector.jsx
│   │   │   │
│   │   │   ├── 📂 Layouts/           # Layout components
│   │   │   │
│   │   │   ├── 📂 Loader/            # Loading spinners
│   │   │   │
│   │   │   ├── 📂 animations/        # Animation components
│   │   │   │   └── PageTransition.jsx
│   │   │   │
│   │   │   └── ServicesMarquee.jsx   # Service showcase
│   │   │
│   │   ├── 📂 context/               # React Context API providers
│   │   │   ├── userContext.jsx       # User state management
│   │   │   └── themeContext.jsx      # Theme state management
│   │   │
│   │   ├── 📂 pages/                 # Page components (route-based)
│   │   │   ├── 📂 Auth/              # Login/Signup pages
│   │   │   ├── 📂 Home/              # Home/Dashboard
│   │   │   ├── 📂 InterviewPrep/     # Interview preparation
│   │   │   ├── 📂 InterviewExperiences/ # Shared experiences
│   │   │   ├── 📂 ResumeBuilder/     # Resume builder
│   │   │   ├── 📂 NotesBooks/        # Reference books
│   │   │   ├── 📂 ProjectIdeas/      # Project ideas
│   │   │   └── 📂 OpenSource/        # Open source resources
│   │   │
│   │   ├── 📂 utils/                 # Utility functions
│   │   │   ├── apiPaths.js           # API endpoints
│   │   │   ├── axiosInstance.js      # Axios configuration
│   │   │   ├── animations.js         # Animation utilities
│   │   │   ├── helper.js             # General helpers
│   │   │   ├── uploadimage.js        # Image upload utility
│   │   │   └── data.js               # Static data
│   │   │
│   │   ├── 📂 assets/                # Images, icons, media
│   │   ├── App.jsx                   # Main App component
│   │   ├── main.jsx                  # React entry point
│   │   ├── App.css                   # Global styles
│   │   └── index.css                 # Base styles
│   │
│   ├── vite.config.js                # Vite configuration
│   ├── eslint.config.js              # ESLint rules
│   ├── tailwind.config.js            # Tailwind CSS config
│   ├── package.json
│   └── index.html
│
├── .gitignore                         # Git ignore rules
├── LICENSE                           # MIT License
└── README.md                         # This file

🤝 Contributing Guidelines

We love contributions from the community! PrepPilot is better because of talented developers like you. Here's how you can help:

🎯 How to Get Started

Fork the repository on GitHub

# Fork via GitHub UI, then:
git clone https://github.com/YOUR_USERNAME/PrepPilot.git
cd PrepPilot

Create a feature branch with a descriptive name

git checkout -b feature/add-amazing-feature
# or
git checkout -b fix/resolve-critical-bug

Make your changes following our code style
- Write clean, readable code
- Add comments for complex logic
- Keep components modular and reusable
- Follow existing naming conventions

Test thoroughly

# Test your changes locally
npm run dev    # Frontend
npm run test   # If tests exist

Commit with clear messages using conventional commits

git commit -m "feat: add new AI model integration"
git commit -m "fix: resolve authentication timeout issue"
git commit -m "docs: update API documentation"

Push and create a Pull Request

git push origin feature/add-amazing-feature

📋 Types of Contributions We Welcome

Type	Examples	Priority
🐛 Bug Fixes	Fix crashes, errors, or unexpected behaviors	High
✨ Features	New tools, integrations, or functionality	Medium
📚 Documentation	README updates, API docs, code comments	Medium
🎨 UI/UX	Design improvements, accessibility fixes	Medium
⚡ Performance	Optimize queries, reduce load time	High
🧪 Tests	Add unit tests, integration tests	Medium

📝 Pull Request Checklist

Before submitting your PR, ensure:

Code follows the project's style guide
You've tested your changes locally
You've updated relevant documentation
Your PR title clearly describes the change
Your PR description explains what and why
You've linked any related issues
No console errors or warnings
You've added/updated tests if applicable

🚫 Code Style Guidelines

Frontend (React/JavaScript):

// Use functional components with hooks
const MyComponent = ({ prop1, prop2 }) => {
  return <div>{prop1}</div>;
};

// Use meaningful variable names
const userAuthToken = localStorage.getItem('authToken');

// Add JSDoc comments for complex functions
/**
 * Fetches interview questions for a specific role
 * @param {string} role - The job role
 * @returns {Promise<Array>} Array of questions
 */
const fetchQuestions = async (role) => { ... };

Backend (Node.js/Express):

// Use async/await
const getUser = async (req, res) => {
  try {
    const user = await User.findById(req.params.id);
    res.json(user);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
};

// Use meaningful error messages
throw new Error("User not found with the provided email");

🐛 Found a Bug?

Check existing issues to avoid duplicates
Create a new issue with:
- Clear, descriptive title
- Step-by-step reproduction instructions
- Expected vs actual behavior
- Screenshots/screencasts if applicable
- Your environment (OS, Browser, Node version)

💡 Suggesting Enhancements?

Use the discussion section or create an issue
Describe the problem the enhancement solves
Provide examples of how it would work
Explain the benefits to users

📞 Need Help?

💬 Open a discussion for questions
🐛 Create an issue for bugs
📧 Contact maintainers for sensitive issues
🤖 Check our FAQ section (coming soon)

� Troubleshooting & FAQs

Common Issues & Solutions

Issue	Cause	Solution
401 Unauthorized Error	Invalid or expired JWT token	Clear browser localStorage and re-login
CORS Error	Frontend & backend origins mismatch	Verify `FRONTEND_ORIGIN` matches exactly
404 API Not Found	Incorrect API base URL	Check `VITE_BACKEND_URL` in env file
MongoDB Connection Failed	Invalid connection string	Verify `MONGO_URI` and IP whitelist
Gemini API Error	Invalid or missing API key	Check `GEMINI_API_KEY` in .env
Port Already in Use	Another process using the port	Change `PORT` in .env or kill existing process
Mixed Content Warning	HTTP frontend accessing HTTPS backend	Use HTTPS for both in production
Nodemon not reloading	File watch issue	Delete node_modules and reinstall

Getting Help

# Check Node version
node --version

# Check npm version
npm --version

# Test MongoDB connection
mongosh "your_connection_string"

# View backend logs
npm run dev  # Shows server logs

# Clear npm cache if installation fails
npm cache clean --force
npm install

📖 API Documentation

Authentication Endpoints

POST   /api/auth/register       - Register new user
POST   /api/auth/login          - Login user
POST   /api/auth/logout         - Logout user
GET    /api/auth/profile        - Get user profile
PUT    /api/auth/profile        - Update user profile

AI Endpoints

POST   /api/ai/generate         - Generate interview questions
POST   /api/ai/explain          - Get detailed explanations
POST   /api/ai/evaluate         - Evaluate user answer

Question Endpoints

GET    /api/questions           - Get all questions
GET    /api/questions/:id       - Get single question
POST   /api/questions           - Create question (admin)
PUT    /api/questions/:id       - Update question (admin)
DELETE /api/questions/:id       - Delete question (admin)

Resume Endpoints

GET    /api/resume              - Get user resumes
POST   /api/resume              - Create resume
PUT    /api/resume/:id          - Update resume
DELETE /api/resume/:id          - Delete resume

For detailed API documentation, see API.md (if available)

🚀 Deployment Guide

Deploy Backend to Heroku

# Install Heroku CLI
npm install -g heroku

# Login to Heroku
heroku login

# Create new app
heroku create your-app-name

# Set environment variables
heroku config:set MONGO_URI=your_mongodb_url
heroku config:set JWT_SECRET=your_jwt_secret
heroku config:set GEMINI_API_KEY=your_api_key

# Deploy
git push heroku main

Deploy Frontend to Vercel

# Install Vercel CLI
npm install -g vercel

# Deploy
vercel

Deploy with Docker

# Build and push to Docker Hub
docker build -t username/preppilot:latest .
docker push username/preppilot:latest

# Pull and run on server
docker pull username/preppilot:latest
docker run -p 8000:8000 --env-file .env username/preppilot:latest

📄 License

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

The MIT License is a permissive open-source license that allows you to:

✅ Use for personal or commercial purposes
✅ Modify the source code
✅ Distribute copies
✅ Include the license in distributions

Conditions:

Include the license and copyright notice

🙌 Acknowledgments & Credits

This project stands on the shoulders of amazing open-source projects and communities:

🤖 AI & Technology

Google Gemini API - Powering intelligent question generation and explanations
React Team - For the revolutionary UI library and amazing community
Vite Team - Lightning-fast build tool that transformed frontend development
Tailwind Labs - Beautiful utility-first CSS framework

📚 Libraries & Frameworks

Express.js - Elegant web framework for Node.js
MongoDB - Flexible and scalable NoSQL database
Mongoose - Beautiful MongoDB object modeling
Monaco Editor - Incredible code editor from VS Code
Framer Motion - Production-ready animation library

👥 Community & Inspiration

Community Contributors - Everyone who reported bugs and suggested features
Open Source Community - For continuous inspiration and support
Developers & Educators - Who shared knowledge and best practices

📖 Resources Used

DSA Resources - Striver's SDE Sheet
NeetCode - Curated DSA problems
GeeksforGeeks - Educational content

🎯 Roadmap

🔄 In Development

🌟 Planned Features

Multi-language support
Spaced repetition system
Integration with LeetCode
Machine learning-based recommendations
Interview experience matching
Premium tier with advanced features

🚀 Future Vision

💬 Community & Support

Get Connected

💌 Email: contact@preppilot.com
🐦 Twitter: @PrepPilot
💻 GitHub Issues: Report bugs here
💬 Discussions: Ask questions here
🤝 Discord: Join our community

Support This Project

If PrepPilot helped you land that dream job or ace your interview, consider:

⭐ Star this repository - It helps more people discover PrepPilot
📢 Share with others - Tell your friends and colleagues
🐛 Report bugs - Help us improve the platform
💡 Suggest features - Your ideas shape the future
🤝 Contribute code - Help develop new features
☕ Buy me a coffee - Support ongoing development

💖 Built with passion by developers, for developers

Made with ❤️ for the tech community

"Your success is our mission. Every question you solve is one step closer to your dream job." 🎯

Name		Name	Last commit message	Last commit date
Latest commit History 9 Commits
backend		backend
frontend		frontend
.gitignore		.gitignore
LICENSE		LICENSE
README.md		README.md

Folders and files

Latest commit

History

Repository files navigation

PrepPilot - AI-Powered Interview Preparation Platform

🚀 About PrepPilot

✨ Key Features

🛠️ Technology Stack

Frontend Architecture

Backend Architecture

Development & DevOps

📦 Complete Dependency Stack

⚡ Quick Start Guide

Prerequisites

📥 Installation Steps

1️⃣ Clone the Repository

2️⃣ Backend Setup

3️⃣ Frontend Setup

4️⃣ Environment Configuration

5️⃣ Start Development Servers

6️⃣ Access the Application

🐳 Docker Setup (Optional)

📁 Project Structure

🤝 Contributing Guidelines

🎯 How to Get Started

📋 Types of Contributions We Welcome

📝 Pull Request Checklist

🚫 Code Style Guidelines

🐛 Found a Bug?

💡 Suggesting Enhancements?

📞 Need Help?

� Troubleshooting & FAQs

Common Issues & Solutions

Getting Help

📖 API Documentation

Authentication Endpoints

AI Endpoints

Question Endpoints

Resume Endpoints

🚀 Deployment Guide

Deploy Backend to Heroku

Deploy Frontend to Vercel

Deploy with Docker

📄 License

🙌 Acknowledgments & Credits

🤖 AI & Technology

📚 Libraries & Frameworks

👥 Community & Inspiration

📖 Resources Used

🎯 Roadmap

🔄 In Development

🌟 Planned Features

🚀 Future Vision

💬 Community & Support

Get Connected

Support This Project

💖 Built with passion by developers, for developers

Made with ❤️ for the tech community

⭐ If this project helped you, please give it a star! Your support means everything! 🌟

About

Resources

License

Uh oh!

Stars

Watchers

Forks

Packages 0

Uh oh!

Contributors

Uh oh!

Languages

Packages