🤖 InterviewAI — AI-Powered Mock Interview Platform

A full-stack web application that simulates real job interviews using AI. Candidates answer voice questions from an animated AI interviewer, receive instant scoring, and get detailed feedback reports.

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📸 Features

• 🎙️ Live Voice Interview — Split-screen video call UI with webcam + AI robot avatar
• 🧠 AI-Generated Questions — Tailored to your resume, role, and experience level
• 📄 Resume Analysis — Upload PDF, AI extracts skills and projects automatically
• 📊 Real-Time Scoring — Technical knowledge, communication, and relevance scored per answer
• 📋 Detailed Reports — Strengths, improvements, skill suggestions, study topics
• 📈 Progress Tracking — Full history of all sessions and scores
• 🔍 ATS Resume Analyzer — Role-specific ATS score with formatting, grammar, and keyword checks
• 📝 Resume Generator — Build and download a professional ATS-friendly resume
• 🔐 JWT Authentication — Secure signup/login system
• 📱 Fully Responsive — Mobile, tablet, and desktop

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🏗️ Tech Stack

Layer	Technology
Frontend	React 18 + Vite + Tailwind CSS
Backend	Node.js + NestJS + TypeScript
Database	MongoDB Atlas (Mongoose)
AI	Google Gemini API
Speech	Web Speech API (browser-native)
Auth	JWT + Passport
PDF Parsing	pdf-parse
Password Hashing	bcryptjs

⚡ Backend migrated from Python FastAPI to NestJS — all API endpoints, business logic, and Gemini prompts are 100% preserved.

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📁 Project Structure

ai-mock-interview/
├── README.md
│
├── backend/                          # NestJS Backend
│   ├── nest-cli.json
│   ├── package.json
│   ├── tsconfig.json
│   ├── .env                          # ⚠️ Never commit this
│   ├── .env.example
│   ├── .gitignore
│   └── src/
│       ├── main.ts                   # App entry point, CORS config
│       ├── app.module.ts             # Root module
│       ├── app.controller.ts         # Health + root endpoints
│       ├── config/
│       │   ├── configuration.ts      # Env variable loader
│       │   └── database.config.ts    # MongoDB connection factory
│       ├── auth/                     # JWT auth module
│       │   ├── auth.controller.ts
│       │   ├── auth.service.ts
│       │   ├── auth.module.ts
│       │   ├── jwt.strategy.ts
│       │   ├── dto/auth.dto.ts
│       │   ├── guards/jwt-auth.guard.ts
│       │   └── schemas/user.schema.ts
│       ├── resume/                   # Resume upload + parsing
│       │   ├── resume.controller.ts
│       │   ├── resume.service.ts
│       │   ├── resume.module.ts
│       │   ├── resume-parser.service.ts
│       │   └── schemas/resume.schema.ts
│       ├── interview/                # Interview session management
│       │   ├── interview.controller.ts
│       │   ├── interview.service.ts
│       │   ├── interview.module.ts
│       │   ├── dto/interview.dto.ts
│       │   └── schemas/interview.schema.ts
│       ├── ats/                      # ATS resume analyzer
│       │   ├── ats.controller.ts
│       │   ├── ats.service.ts
│       │   └── ats.module.ts
│       ├── resume-generator/         # HTML resume builder
│       │   ├── resume-generator.controller.ts
│       │   ├── resume-generator.service.ts
│       │   ├── resume-generator.module.ts
│       │   └── dto/resume-generator.dto.ts
│       └── ai/                       # Gemini AI service
│           ├── gemini.service.ts
│           └── ai.module.ts
│
└── frontend/
    ├── index.html
    ├── vite.config.js
    ├── tailwind.config.js
    ├── package.json
    ├── .env                          # ⚠️ Never commit this
    ├── .gitignore
    └── src/
        ├── App.jsx
        ├── main.jsx
        ├── index.css
        ├── context/
        │   └── AuthContext.jsx
        ├── services/
        │   └── api.js
        ├── hooks/
        │   ├── useSpeechSynthesis.js
        │   └── useSpeechRecognition.js
        ├── components/
        │   └── AppLayout.jsx
        └── pages/
            ├── Landing.jsx
            ├── Login.jsx
            ├── Signup.jsx
            ├── Explore.jsx
            ├── InterviewHub.jsx
            ├── Scores.jsx
            ├── ResumeUpload.jsx
            ├── LiveInterview.jsx
            └── InterviewReport.jsx

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⚡ Quick Start

Prerequisites

• Node.js 18+
• MongoDB Atlas account (free tier)
• Google AI Studio account (free Gemini API key)

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1. Clone the repo

git clone https://github.com/Pranav18M/Ai-mock-interview-.git
cd Ai-mock-interview-

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2. Backend Setup

cd backend
npm install

Create backend/.env:

MONGODB_URL=mongodb+srv://<username>:<password>@<cluster>.mongodb.net/ai_mock_interview?retryWrites=true&w=majority
DATABASE_NAME=ai_mock_interview
JWT_SECRET=your_super_secret_key_change_this
JWT_ALGORITHM=HS256
ACCESS_TOKEN_EXPIRE_MINUTES=1440
GEMINI_API_KEY=your_gemini_api_key_here
OPENAI_API_KEY=
PORT=8000

Start the backend:

npm run start:dev

API running at: http://localhost:8000

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3. Frontend Setup

cd frontend
npm install

Create frontend/.env:

VITE_API_URL=http://localhost:8000

Start the frontend:

npm run dev

App running at: http://localhost:5173

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🔑 Getting API Keys

MongoDB Atlas

1. Visit mongodb.com/atlas → create free cluster
2. Database Access → add a user with password
3. Network Access → add IP 0.0.0.0/0 for development
4. Connect → Drivers → copy connection string into .env

Gemini API Key

1. Visit aistudio.google.com/app/apikey
2. Click Create API Key → copy into .env

⚠️ Warning: If your Gemini key is pushed to a public GitHub repo, Google auto-revokes it. Always use .env and keep it in .gitignore.

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🌐 API Reference

Auth

Method	Endpoint	Description	Auth
POST	/auth/signup	Register new user	❌
POST	/auth/login	Login, receive JWT	❌

Resume

Method	Endpoint	Description	Auth
POST	/resume/upload	Upload + parse PDF resume	✅
GET	/resume	Get current resume data	✅

Interview

Method	Endpoint	Description	Auth
POST	/interview/generate-questions	AI generates 5 questions	✅
POST	/interview/submit-answer	Submit + score one answer	✅
POST	/interview/complete/:id	Finalize + generate report	✅
GET	/interview/history	All past sessions	✅
GET	/interview/report/:id	Full report for session	✅
POST	/interview/greeting	AI interviewer greeting	✅
POST	/interview/intro-response	AI response to user intro	✅

ATS Analyzer

Method	Endpoint	Description	Auth
POST	/ats/analyze	Analyze resume ATS score	✅

Resume Generator

Method	Endpoint	Description	Auth
POST	/resume-gen/preview	Generate resume HTML preview	✅
POST	/resume-gen/download	Download resume as PDF	✅

Health

Method	Endpoint	Description
GET	/	API info
GET	/health	Health check

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🎯 How It Works

User signs up / logs in
        ↓
Uploads PDF resume → AI extracts skills, projects, experience
        ↓
Selects job role + difficulty (beginner / intermediate / advanced)
        ↓
Backend calls Gemini API → generates 5 tailored interview questions
        ↓
Live interview screen:
  ┌──────────────────┬──────────────────┐
  │  AI Robot Image  │  User Webcam     │
  │  (video call)    │  (live feed)     │
  └──────────────────┴──────────────────┘
  AI reads question aloud → User speaks answer → Transcript captured
        ↓
Each answer scored by Gemini (1–10):
  • Technical knowledge
  • Communication clarity
  • Relevance to question
        ↓
After 5 questions → Full report generated:
  • Overall score ring
  • Per-question breakdown
  • Strengths / Areas to improve
  • Skill suggestions + study topics

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🤖 AI Features

Powered by Google Gemini API with automatic model fallback:

Priority	Model	Free Limit
1st	gemini-1.5-flash	1500 req/day
2nd	gemini-1.5-flash-8b	1500 req/day
3rd	gemini-1.0-pro	60 req/min

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🗄️ MongoDB Collections

Collection	Description
users	User accounts
resumes	Parsed resume data per user
interviews	Sessions, answers, scores, feedback

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📱 Responsive Design

Breakpoint	Layout
Mobile < 768px	Hamburger nav, stacked video panels, single column
Tablet 768–900px	Horizontal nav, 2-col grids
Desktop > 900px	Full split layout, sticky image panel, 4-col grids

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🚀 Production Deployment

Backend — Render / Railway / Fly.io

# Start command
npm run start:prod

# Set all .env variables in your platform dashboard
# Update CORS origins in main.ts to allow only your frontend domain

Frontend — Vercel / Netlify

npm run build
# Deploy the dist/ folder
# Set environment variable: VITE_API_URL=https://your-backend-url.com

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🛠️ Development Notes

Note	Detail
Speech Recognition	Requires Chrome or Edge — Firefox not supported
Webcam	Browser permission prompt on first interview load
CORS	Configured for localhost + Vercel — restrict for production
LiveInterview routing	Requires location.state from setup page
PDF Upload	Max 5MB, PDF only

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📦 Backend Dependencies

@nestjs/common, @nestjs/core, @nestjs/config
@nestjs/mongoose, mongoose
@nestjs/passport, @nestjs/jwt, passport-jwt
bcryptjs
pdf-parse
class-validator, class-transformer
axios
multer

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🤝 Contributing

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

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📄 License

MIT License — see LICENSE for details.

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👤 Author

Pranav — Full Stack Developer

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Built with React, NestJS, MongoDB Atlas, and Google Gemini AI