System Design Full Course - What is UML Diagrams | Class & Sequence Diagrams with Real Examples

Welcome to Lecture 4 of the Ultimate Low-Level Design (LLD) Series by Coder Army! Today is Day 4 for #lowleveldesign #systemdesign #8weeksLLdchallenge. We are doing 8 weeks challenge and going to complete the whole course within the duration with quality content on Youtube. Let’s learn LLD like never before and attain advance level mastery on this subject. In this lecture, we break down one of the most powerful concepts in Object-Oriented Programming — *Inheritance and Polymorphism* — with clear real-world analogies and practical code demonstrations. In this session, we explore one of the most essential tools for software engineers and system designers — *UML Diagrams (Unified Modeling Language)*. 📌 *In this video, you’ll learn:* - What is UML and why it’s used in software design - How to draw and understand *Class Diagrams* (with real-world examples) - How to create and analyze *Sequence Diagrams* to visualize system interactions - How UML helps in real-life Low-Level Design and interview discussions Whether you’re preparing for tech interviews, working on software architecture, or building your own projects — understanding UML is a must for clear, maintainable, and scalable code design. Join Coder Army Whatsapp Group: https://whatsapp.com/channel/0029Va6H0tbHVvTbcuT99Y1f Code and Notes: Github : https://github.com/adityatandon15/LLD Connect with Aditya Tandon Instagram : https://www.instagram.com/adityatandon2 LinkedIn : https://www.linkedin.com/in/adityatandon2 Twitter : https://x.com/adityatandon02 Timestamps: 00:00 Introduction to UML Diagrams 02:14 Types of UML 05:46 Class Diagrams 06:42 Representing class structure in UML 17:30 Representing class Association in UML 22:03 Representing Inheritance in UML 25:40 Composition Explained 27:10 Representing Simple Association 30:12 Representing Aggregation 34:34 Representing Composition 43:34 Exercise Problem 44:48 Conclusion for Class Diagrams 46:43 Sequence Diagram 01:00:37 How to draw Sequence Diagrams #uml #LowLevelDesign #Abstraction #Encapsulation #LLD #SystemDesign #SoftwareEngineering #TechInterviews #CoderArmy #CodingConcepts