Strategy pattern
A shop ledger page, 1899. Every line adds up.
LLD Series: Splitwise / Expense Sharing (Low-Level Design)
Design Splitwise. Users add expenses and split them equally, by exact amounts, or by percentage. Show who owes whom. Add a 'simplify debts' feature that minimises the number of transactions.
18 min read
LLD Series: Parking Lot (Low-Level Design)
Design a multi-floor parking lot. Vehicles enter, get a ticket and a spot, and pay on exit. Support different vehicle types and pricing. Write working code in 60 minutes.
15 min read