Design an ATM System

Medium

+200 XP

PRO

Low Level DesignLLDSystem DesignOOPConcurrency

Design an ATM (Automated Teller Machine) system that allows users to check balances, withdraw cash, and deposit money after secure PIN authentication. The system communicates with the bank's backend to verify accounts and process transactions, uses a cash dispenser that supports multiple denominations, and handles concurrent transactions safely. The ATM should have distinct states (idle, card inserted, authenticated) with different behaviors in each state, and the cash dispenser should support multiple denominations and handle cases where one denomination cannot fulfill the request.

WELCOME TO BANK

Insert Card to Begin

Security Keypad v2.0
(Use PIN: 1234)

What You'll Build

The ATM should allow users to perform basic actions such as checking their account balance, withdrawing cash, and depositing cash.
Users must authenticate themselves before using the ATM by inserting their ATM card and entering their PIN (Personal Identification Number).
The ATM system should communicate with the bank's main system to verify the user's account and confirm and process transactions like withdrawals and deposits.
The ATM should include a cash dispenser that gives money to users when they withdraw cash, supporting multiple note denominations.
The system must work correctly when multiple users or transactions happen at the same time, making sure account data stays accurate and consistent.
...and more

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Step-by-Step Guidance

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Design Patterns

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Complete Solutions

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