DSA · LLD
Low-level design
Object-oriented design walkthroughs — Splitwise, Parking Lot, Vending Machine — with the tradeoffs spelled out.
- 9m
Parking Lot
Multi-floor parking with size-based slot allocation, ticket lifecycle and pricing strategy.
lldoopdesign - 9m
Splitwise (Expense Sharing)
Track group expenses with arbitrary splits and minimise inter-user settlement transactions.
lldoopgraph - 6m
Tic-Tac-Toe
Tiny game, but a great vehicle for clean state machines and pluggable AI strategies.
lldoopgame - 6m
Snake and Ladder
Game loop with chained jumps, dice strategy and configurable board.
lldoopgame - 7m
Vending Machine
A textbook state machine — Idle / HasMoney / Dispensing / Refunding.
lldstate-machineoop - 7m
URL Shortener (Object model)
Class-level design for a Bit.ly clone — stores, generators, and the rate-limit decorator.
llddesign - 8m
Ride Hailing (LLD slice)
Object model for booking a ride — Rider, Driver, Trip, MatchingStrategy, FareCalculator.
llddesign - 7m
Notification Service
Multi-channel notifications (email/SMS/push) with template, retry and rate-limit decorators.
llddesign