System Design (LLD) Full Course

By Coder Army

Master low-level design (LLD) and write production-ready, scalable code. This comprehensive guide bridges the gap between object-oriented theory and practical implementation, covering SOLID principles, design patterns, and UML modeling. Through hands-on projects like building a notification engine and document editor, you will develop the clean-coding habits and architectural intuition needed to ace elite backend engineering interviews.

Table of Contents

System Design (LLD) Full Course

Table of Contents

Introduction To System Design

OOPs Real-World Examples | OOPs Pillars | Abstraction | Encapsulation

Inheritance & Polymorphism in OOPs

What is UML Diagrams | Class & Sequence Diagrams with Real Examples

SOLID Design Principles | Complete Guide with Code Examples

SOLID Design Principles | part 2

Build Google Docs | A Real-World LLD Project | Document Editor LLD |

Strategy Design Pattern Explained with Real-World Example | Design Patterns in LLD

Factory Design Pattern | Simple, Factory Method & Abstract Factory with Real-Life Examples

Singleton Design Pattern | Thread-Safe, Lazy & Eager Initialization + Real Use Cases

Build Zomato Food Delivery App | System Design

Observer Design Pattern Explained | Real-Life Use Case + Code Example

Decorator Pattern Explained | Real-world use case + Code | Design patterns in LLD

Build Your Own Notification Engine | System Design

Command Design Pattern | Real-world use case + Code | Design patterns in LLD

Adapter Design Pattern | Real-world use case + Code | Design patterns in LLD

Facade Design Pattern | Real-world use case + Code | Design patterns in LLD

Build Spotify, Music Player App | System Design

Composite Design Pattern | Build File System (UML & Code) | System Design

Template Method Pattern | Step-by-Step Example (UML + Code)

Proxy Design Pattern | Virtual Proxy | Protection Proxy | Remote Proxy

Chain of Responsibility Pattern | Build Cash Dispenser(UML & Code) | System Design

Build Payment Gateway System | System Design

Build Discount Coupon Engine | System Design

Bridge Pattern | Real-world use case + Code | System Design

Build Zepto | 10-Mins Quick Commerce | Inventory Management | System Design

Build Tinder | Dating Site | System Design

Builder Design Pattern | Classic Builder | Step Builder | UML + Code | System Design

Iterator Design Pattern | UML + Code | System Design

Flyweight Design Pattern | UML + Code | System Design

Build Splitwise Clone | Expense Splitting App | System Design

State Design Pattern | Build Vending Machine (UML & Code) | System Design

Build Tic Tac Toe Game | UML + Code | System Design

Build Snake and Ladder Game | UML + Code | System Design

Mediator Design Pattern | Build Chat Room | UML + Code | System Design

Prototype Design Pattern | UML + Code | System Design

Build Chess Game | UML + Code | System Design

Visitor Design Pattern | UML + Code | System Design

Memento Design Pattern | UML + Code | System Design

Null Object Pattern | Anti-Patterns in System Design