Object-Oriented Design (LLD) Course: Complete Design Patterns for Interviews

Created by Mukul Raina (Senior Software Engineer & Tech Lead at Microsoft, Oxford MSc), this course provides a complete foundation for Low-Level Design (LLD) interviews at FAANG and top tech companies. It covers OOP principles (encapsulation, abstraction, inheritance, polymorphism, composition vs inheritance, interface vs abstract class) with interview-focused practice problems, SOLID principles (SRP, OCP, LSP, ISP, DIP) with real-world violations and fixes, and 23 design patterns organized by type—Creational (Factory, Abstract Factory, Builder, Singleton), Structural (Adapter, Decorator, Facade, Proxy), and Behavioral (Strategy, Observer, Command, State, Chain of Responsibility, Template Method). The course also includes a pattern selection framework, signal-to-pattern recognition, multi-pattern worked examples (checkout flow, messaging platform, file storage), and anti-pattern coverage (over-engineering, premature abstraction, circular dependencies)—equipping you with a practical toolkit to design clean, extensible, and maintainable systems in real interview contexts.

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