Tech Stack: Node.js, Express, MongoDB, Mongoose, Zod, JWT, bcrypt, ws (WebSocket)

Duration: 3 hours

Overview

Build a complete backend system with:

• Authentication (signup, login, me)
• Role-based access control (teacher & student)
• Class management CRUD
• WebSocket-based live attendance
• Attendance persistence to MongoDB

Key Assumption: Only ONE class session can be active at a time on WebSocket. No room management needed - all broadcasts go to all connected clients.

Response Format Standard

Success Response

{
  "success": true,
  "data": { ... }
}

Error Response

{
  "success": false,
  "error": "Error message",
}

All HTTP responses MUST follow this format!

JWT Authentication