Week-11

Assignment: Payments Backend + Frontend

Tech Stack

• Node.js
• Express
• MongoDB (Mongoose)
• JWT
• Zod

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Folder Structure

backend/
  ├── config.js
  ├── db.js
  ├── index.js
  ├── middleware.js
  └── routes/
      ├── user.js
      ├── account.js
      └── index.js

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Base Route

/api/v1

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Schemas

User

{
  username: String,   // email, unique
  password: String,
  firstName: String,
  lastName: String
}

Account

{
  userId: ObjectId,   // reference to User
  balance: Number
}

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What to Build

User Routes

• POST /user/signup
• POST /user/signin
• PUT /user/ (protected)
• GET /user/bulk?filter=

Account Routes

• GET /account/balance (protected)
• POST /account/transfer (protected)

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Requirements

• JWT auth middleware
• Attach userId from token
• Create account on signup with random balance
• Use MongoDB transactions for transfer
• Validate inputs using Zod

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Frontend (Required)

Build a simple frontend for this system.

Guidelines:

• Must support:

  • Signup / Signin
  • View balance
  • Search users
  • Send money

• UI/UX is up to you — design it your way

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Output

• Working backend
• Functional frontend connected to backend