🎯 Low-Level Design Ultimatum

Learn the four pillars of OOP — Abstraction, Encapsulation, Inheritance, and Polymorphism — that form the foundation of good system design.

Understand how to read and create UML class diagrams to visualize your system architecture and communicate design decisions.

Explore the key differences and use cases between interfaces and abstract classes — a common interview question.

Deep dive into the five SOLID principles that guide good object-oriented design for maintainable, scalable code.

Object creation patterns: Factory Method, Abstract Factory, Builder, Prototype, and Singleton with real-world use cases.

Object composition patterns: Adapter, Bridge, Composite, Decorator, Facade, Flyweight, and Proxy.

Object interaction patterns: Observer, Strategy, Command, Iterator, Chain of Responsibility, and more.

Learn the Circuit Breaker pattern for building resilient, fault-tolerant distributed systems — essential for senior roles.

Design a parking lot management system with multiple levels, spot types, and automated ticketing.

Build a complete airline booking and management platform with flights, reservations, and seat management.

Design Amazon pickup lockers with package assignment, slot management, and retrieval workflows.

Implement an intelligent elevator controller for multi-floor buildings with scheduling algorithms.

Create a comprehensive hotel booking and reservation system with rooms, guests, and billing.

Design a car rental platform with fleet management, reservations, and payment processing.

Build a ride-sharing app with driver-rider matching, trip management, and pricing algorithms.

Implement a movie ticket booking system with seat selection, showtime management, and concurrency handling.

Design a library system with book catalog, member management, loans, and fine calculation.

Build a Q&A platform with questions, answers, voting, reputation system, and tagging.

Design a professional networking platform with user profiles, connections, posts, and feed ranking.

Implement a social media platform with posts, comments, likes, friend graph, and newsfeed generation.

Curated collection of real Amazon low-level design interview questions with expected approaches and solutions.

Curated collection of real Uber low-level design interview questions covering their core systems and platforms.

Design an ATM machine with card processing, PIN validation, and transaction management.

Implement a distributed cache with LRU/LFU eviction policies, TTL support, and thread safety.

Build a chess game with piece movement validation, check detection, and game state management.

Design an in-memory file system with directory tree structure, file operations, and path navigation.

Implement an efficient hit counter for tracking API request rates with sliding window algorithms.

Build a text editor with full Undo & Redo functionality using the Command pattern.