🤖 AI-Driven Technical Interview Simulation & Performance Analytics Platform

An intelligent full-stack platform that simulates real-world technical interviews using AI, evaluates candidate responses in real time, and delivers rich performance analytics and personalized feedback.

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📌 Table of Contents

• Overview
• Features
• Tech Stack
• Architecture
• Project Structure
• Getting Started
  • Prerequisites
  • Installation
  • Environment Variables
  • Running the App
• API Reference
• Screenshots
• Contributing
• License

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🧠 Overview

This platform provides a fully AI-powered mock interview experience — from resume parsing and dynamic question generation to speech-to-text answer capture, automated evaluation, and actionable performance reports.

Candidates can:

• Upload their resume to generate role-specific questions
• Speak or type their answers during a live interview session
• Receive instant AI-scored feedback with detailed analytics
• Review their complete interview history over time

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✨ Features

Feature	Description
🔐 Auth System	JWT-based register/login with bcrypt password hashing
📄 Resume Parsing	Upload PDF resume → AI extracts skills, experience, and projects
🎯 Dynamic Question Generation	Google Gemini generates tailored interview questions per role and skill level
🎤 Speech-to-Text	AssemblyAI transcribes spoken answers in real time
🤖 AI Evaluation	Gemini scores each answer on accuracy, depth, and communication
📊 Performance Analytics	Per-question scores, overall rating, strengths, and improvement areas
📝 Interview History	Past sessions stored in MongoDB; browseable from the dashboard
💻 Code Editor	Monaco Editor integration for coding round questions
🔔 Toast Notifications	Real-time feedback with react-hot-toast

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🛠 Tech Stack

Frontend

Technology	Purpose
React 19 + Vite 6	UI framework and build tool
React Router v7	Client-side routing
Axios	HTTP client for API calls
Monaco Editor (@monaco-editor/react)	In-browser code editor for coding questions
Web Speech API	Browser-native speech recognition (ConversationalMic)
MediaRecorder API	Browser-native audio recording (VoiceRecorder)
React Icons	Icon library
React Hot Toast	Notification system

Backend

Technology	Purpose
Node.js v18+ + Express 5	REST API server
MongoDB Atlas + Mongoose 9	Cloud database and ODM
JSON Web Tokens (JWT)	Stateless authentication
bcryptjs	Password hashing
Multer (memory storage)	File uploads — PDF resume & audio
pdfjs-dist (legacy build)	PDF text extraction in Node.js
@google/genai	Google Gemini 2.5 Flash AI integration
AssemblyAI SDK	Speech-to-text transcription (speech_model: universal)
Murf AI REST API	Text-to-speech — Natalie voice (MP3, 24kHz)
dotenv	Environment variable management

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🏗 Architecture

┌──────────────────────────────────────────────────────────────────┐
│                     CLIENT (React 19 + Vite 6)                    │
│                                                                    │
│  LoginPage ──► HomePage ──► InterviewSetupPage                   │
│                                    │                              │
│                              InterviewPage                        │
│                         (VoiceRecorder / CodeEditor)              │
│                                    │                              │
│                         FeedbackPage ◄── HistoryPage             │
└──────────────────────────┬───────────────────────────────────────┘
                           │  REST API over HTTP (Axios)
                           │  Authorization: Bearer <JWT>
┌──────────────────────────▼───────────────────────────────────────┐
│                      SERVER (Express 5 / Node.js)                 │
│                                                                    │
│  POST /api/auth/register|login   GET /api/auth/me                │
│  POST /api/resume/upload         GET  /api/resume                │
│  POST /api/interview/start                                        │
│  POST /api/interview/:id/answer|answer-audio|code|end            │
│  GET  /api/interview/:id                                          │
│  GET|DELETE /api/history[/:id]                                    │
└──────┬─────────────────┬──────────────────┬────────────────┬─────┘
       ▼                 ▼                  ▼                ▼
  MongoDB Atlas    Google Gemini       AssemblyAI         Murf AI
  (Users, Inter-   2.5 Flash           (Speech →          (Text →
   views, Resume)  (Questions &         Text)              Speech
                   Evaluation)                             MP3)

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📁 Project Structure

AI-Driven-Technical-Interview-Simulation/
│
├── client/                               # React + Vite frontend
│   ├── src/
│   │   ├── components/
│   │   │   ├── AudioPlayer/              # Plays Murf TTS audio (base64 MP3)
│   │   │   ├── CodeEditor/               # Monaco Editor wrapper
│   │   │   ├── ConversationalMic/        # Web Speech API live transcription
│   │   │   ├── InterviewCard/            # History card component
│   │   │   ├── Navbar/                   # Top navigation bar
│   │   │   ├── ProtectedRoute/           # JWT route guard
│   │   │   ├── ScoreCard/               # Category score display
│   │   │   └── VoiceRecorder/            # MediaRecorder audio recording
│   │   ├── constants/
│   │   │   ├── difficulty.js             # Difficulty levels + question counts
│   │   │   ├── roles.js                  # Interview role definitions
│   │   │   └── scoreColors.js            # Score-to-color mapping
│   │   ├── context/
│   │   │   └── AuthContext.jsx           # Global auth state (login/logout/user)
│   │   ├── pages/
│   │   │   ├── LoginPage/                # Hero + Sign In / Create Account
│   │   │   ├── HomePage/                 # Dashboard with stats + recent history
│   │   │   ├── InterviewSetupPage/       # 3-step wizard: role → difficulty → resume
│   │   │   ├── InterviewPage/            # Live interview (voice/text/code)
│   │   │   ├── FeedbackPage/             # Detailed AI feedback + category scores
│   │   │   └── HistoryPage/              # Paginated interview history
│   │   ├── services/
│   │   │   ├── api.js                    # Axios instance with JWT interceptor
│   │   │   ├── authService.js            # register, login, getMe, logout
│   │   │   ├── historyService.js         # getHistory, deleteHistoryItem, clearHistory
│   │   │   └── interviewService.js       # upload, start, answer, code, end, get
│   │   ├── App.jsx                       # Route definitions
│   │   ├── App.css                       # Global styles
│   │   └── main.jsx                      # React entry point
│   ├── index.html
│   ├── vite.config.js
│   ├── .env.example
│   └── package.json
│
├── server/                               # Node.js + Express backend
│   ├── src/
│   │   ├── config/
│   │   │   ├── db.config.js              # MongoDB Atlas connection
│   │   │   └── gemini.config.js          # Google GenAI client (Gemini 2.5 Flash)
│   │   ├── constants/
│   │   │   └── prompts.js                # All AI prompt templates
│   │   ├── controllers/
│   │   │   ├── auth.controller.js
│   │   │   ├── resume.controller.js
│   │   │   ├── interview.controller.js   # text/voice/code answer + TTS stream
│   │   │   └── history.controller.js
│   │   ├── middleware/
│   │   │   ├── auth.middleware.js        # JWT verification → req.user
│   │   │   ├── error.middleware.js       # 404 + global error handler
│   │   │   └── upload.middleware.js      # Multer: PDF (10MB) + audio (25MB)
│   │   ├── models/
│   │   │   ├── User.model.js
│   │   │   ├── Interview.model.js        # questions, messages, codeSubmissions, feedback
│   │   │   └── Resume.model.js
│   │   ├── routes/
│   │   │   ├── index.js
│   │   │   ├── auth.routes.js
│   │   │   ├── resume.routes.js
│   │   │   ├── interview.routes.js
│   │   │   └── history.routes.js
│   │   ├── services/
│   │   │   ├── auth.service.js
│   │   │   ├── gemini.service.js         # askGemini() wrapper
│   │   │   ├── assemblyai.service.js     # transcribeAudio() via temp file
│   │   │   ├── murf.service.js           # generateAudio() + streamAudio()
│   │   │   ├── interview.service.js      # full interview state machine
│   │   │   ├── resume.service.js         # PDF parse + upsert to DB
│   │   │   └── history.service.js        # paginated history CRUD
│   │   └── utils/
│   │       ├── jwt.utils.js              # generateToken, verifyToken
│   │       └── prompts.utils.js          # parseGeminiJSON()
│   ├── server.js                         # Entry point
│   ├── .env.example
│   ├── .gitignore
│   └── package.json
│
├── .gitignore
└── README.md

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🚀 Getting Started

Prerequisites

Make sure you have the following installed:

• Node.js v18 or higher
• npm v9 or higher
• A MongoDB Atlas account (free tier works)
• API keys for:
  • Google Gemini
  • AssemblyAI
  • Murf AI (optional — for TTS)

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Installation

1. Clone the repository

   git clone https://github.com/kadapalanikith/AI-Driven-Technical-Interview-Simulation-and-Performance-Analytics-Platform.git
   cd AI-Driven-Technical-Interview-Simulation-and-Performance-Analytics-Platform

2. Install server dependencies

   cd server
   npm install

3. Install client dependencies

   cd ../client
   npm install

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Environment Variables

Server (server/.env)

Copy the template and fill in your values:

cp server/.env.example server/.env

Variable	Description
PORT	Port the Express server runs on (default: 5000)
NODE_ENV	development or production
MONGODB_URI	MongoDB Atlas connection string
JWT_SECRET	Secret key for signing JWT tokens
JWT_EXPIRES_IN	Token expiry duration (e.g. 7d)
GEMINI_API_KEY	Google Gemini API key
MURF_API_KEY	Murf AI text-to-speech key
ASSEMBLYAI_API_KEY	AssemblyAI speech-to-text key
CLIENT_URL	Frontend origin for CORS (e.g. http://localhost:5173)

Client (client/.env)

cp client/.env.example client/.env

Variable	Description
VITE_API_URL	Base URL of the Express API (e.g. http://localhost:5000)

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Running the App

Start the backend server:

cd server
npm run dev

Server starts at http://localhost:5000

Start the frontend (in a new terminal):

cd client
npm run dev

App opens at http://localhost:5173

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📡 API Reference

All API routes are prefixed with /api.

Auth — /api/auth

Method	Endpoint	Auth	Description
POST	/auth/register	❌	Create a new account
POST	/auth/login	❌	Login and get JWT
GET	/auth/me	✅	Fetch authenticated user profile

Resume — /api/resume

Method	Endpoint	Auth	Description
POST	/resume/upload	✅	Upload and parse a PDF resume

Interview — /api/interview

Method	Endpoint	Auth	Description
POST	/interview/start	✅	Start a new interview session
POST	/interview/:id/answer	✅	Submit an answer; get AI feedback
POST	/interview/:id/end	✅	End session and generate final report
GET	/interview/:id	✅	Fetch a specific interview session

History — /api/history

Method	Endpoint	Auth	Description
GET	/history	✅	List all past interviews for the user
GET	/history/:id	✅	Get detailed results of a past interview

Auth header format: Authorization: Bearer <token>

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🤝 Contributing

Contributions are welcome! Please follow these steps:

1. Fork the repository
2. Create a new branch: git checkout -b feature/your-feature-name
3. Make your changes and commit: git commit -m "feat: add your feature"
4. Push to your branch: git push origin feature/your-feature-name
5. Open a Pull Request

Please follow the Conventional Commits standard for commit messages.

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📄 License

This project is licensed under the MIT License.
Feel free to use, modify, and distribute it.

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Built with ❤️ using React, Node.js, and Google Gemini AI