Low-Level Design
Machine-coding's design round
Object-oriented design and design patterns — parking lot, rate limiter, cache and more — with clean class diagrams and the trade-off discussion SDE-1/2 rounds expect.
- OOD & SOLID
- Design patterns
- Class diagrams
- Editorial solutions
- Progress tracking
Sample questions
- MixedCurated set 1Mixed topics
- MixedCurated set 2Mixed topics
- MixedCurated set 3Mixed topics
Low-Level Design & OOD
Object-oriented design problems with editorial solutions — the SDE-2 round, and increasingly a fresher one too.
Core data structures
LRU Cache
Problem + Editorial
HashMapDLL
FreeDesign HashMap
Problem + Editorial
Circular Queue / Deque
Problem + Editorial
Min Stack
Problem + Editorial
Design patterns
Parking Lot System
Strategy + State
SOLID
FreeNotification System
Observer pattern
Payment Module
Strategy pattern
Coffee Shop / Pizza
Decorator pattern
Real-world systems
Elevator System
State machine
Splitwise
Graph + ledger
Tic-Tac-Toe / Chess
OOP modelling
Rate Limiter (LLD)
Token bucket