Chain of responsibility
A shop ledger page, 1899. Every line adds up.
LLD Series: Logger Framework (Low-Level Design)
Asked at: Visa, Mastercard, Amex, PayU (classic machine-coding warm-up; checks patterns knowledge). Interviewers expect: Singleton, Chain of Responsibility, Strategy for formatter/appender, and a...
12 min read
LLD Series: ATM (Low-Level Design)
Design an ATM. A user inserts a card, enters a PIN, and can withdraw cash, deposit or check balance. The machine must dispense the right notes. Model the machine's behaviour so that invalid...
19 min read