Build Discount Coupon Engine | System Design

Welcome to Lecture 24 of the Ultimate Low-Level Design (LLD) Series by Coder Army! fifth week 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 deep-dive LLD tutorial, we’ll design and implement a full-featured *Discount Coupon Engine* in C++/Java then translate the same concepts into Java. You’ll see how to: 1. *Define flexible discount rules* with the *Strategy Pattern* (Flat, Percentage & Capped Percentage) 2. *Wire up a dynamic chain* of coupons using the *Chain of Responsibility*, so multiple offers can apply in sequence or stop when needed 3. *Manage your strategies* and coupons as *Singletons* for global, thread-safe access 4. *Compose your system* step-by-step: from individual Coupon classes to a central CouponManager that registers, lists, and applies discounts 5. *Walk through a sample Cart* to see original vs. final totals, and inspect which promotions fired Whether you’re building a shopping cart, a subscription service, or any application that needs powerful promo-code logic, this LLD session gives you the patterns and code scaffolding to get started. 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 00:00 Introduction 02:14 Requirements 06:54 Happy Flow 09:22 UML Design for Discount Coupon Engine 54:53 Final UML 56:58 Code for Coupon Discount Engine #SystemDesign #LowLevelDesign #LLD #AdapterPattern #DesignPatterns #Cplusplus #JavaDevelopers #UMLDiagrams #TechInterviews #SoftwareEngineering #XMLtoJSON #CleanCode #SoftwareArchitecture #ObjectOrientedDesign #CodingWithExamples #CodeBetter #8WeeksLLDChallenge #JSON