Low Level Design
Deep Dive into Low Level Design (LLD)
Dive into the world of Low-Level Design (LLD) with this comprehensive guide. Whether you're prepping for interviews or strengthening your system design skills, this blog covers it all — essential topics, must-practice questions, core design patterns explained with real-world analogies, and annotated sample code snippets. Perfect for developers aiming to write clean, scalable, and maintainable code.
Cracking system design interviews is no longer limited to just high-level architecture. Companies today (especially product-based ones like Google, Uber, Razorpay, etc.) are increasingly emphasizing Low-Level Design (LLD) to assess your understanding of Object-Oriented Design, Design Patterns, Class Diagrams, and more.
In this blog, I’ll walk you through the LLD preparation roadmap, key concepts, design patterns, and common problems to practice. Plus, I’ve curated a GitHub repository with resources, explanations, and code samples to supercharge your prep.
What is Low-Level Design?#
Low-Level Design (LLD) refers to designing software components at the class and object level, focusing on how individual modules communicate and behave. It deals with:
- Class structures
- Object interactions
- Design principles (like SOLID)
- Design patterns (like Singleton, Factory, Strategy, etc.)
- Real-world use-case implementations
SOLID Principles#
SOLID is an acronym for five fundamental principles of object-oriented programming and design that help create more maintainable, flexible, and robust software.
- S - Single Responsibility Principle
- O - Open Closed Principle
- L - Liskov Substitution Principle
- I - Interface Segmented Principle
- D - Dependency Inversion Principle
Design Patterns#
- Design patterns are reusable solutions to commonly occurring problems in software design.
- They represent best practices and proven approaches that experienced developers have identified and documented over time.
- Categories of design patterns include Creational, Structural, and Behavioral patterns.
- Creational Patterns: Deal with object creation mechanisms (Singleton, Factory, Builder)
- Structural Patterns: Deal with object composition and relationships (Adapter, Decorator, Facade)
- Behavioral Patterns: Deal with communication between objects and assignment of responsibilities (Observer, strategy.Strategy, Command)
More detailed concepts will be added soon!