🏆 LLD Interview Question | Customer Issue Resolution System (PhonePe)

📌 Customer Support System LLD | Asked in PhonePe | Low Level Design Interview Question In this video, I explain the Low Level Design (LLD) of a Customer Support / Issue Resolution System, a real machine coding / LLD interview question recently asked in PhonePe. 🔹 Problem Overview: We need to design a system where: Customers can raise issues against failed/unsuccessful transactions Issues can be of multiple types (Payment, Mutual Fund, Gold, Insurance, etc.) Agents are onboarded with their expertise and can be assigned issues accordingly Issues move through different statuses: Open → In Progress → Resolved Agents can track assigned issues and update resolutions System supports searching issues by ID or customer email Work history of agents can be retrieved 🔹 Features Implemented: ✅ createIssue() – Raise a new issue for a transaction ✅ addAgent() – Onboard agents with expertise ✅ assignIssue() – Assign issues to free agents (waitlist if not available) ✅ getIssues() – Fetch issues by filters (email, type, etc.) ✅ updateIssue() – Update status & resolution notes ✅ resolveIssue() – Mark issues as resolved ✅ viewAgentsWorkHistory() – Track agents’ assigned/resolved issues 🔹 Example Use Cases Covered: Create multiple issues of different types Add agents with different expertise Assign issues dynamically to agents Query issues by customer email and type Update & resolve issues View agent work history 🎯 This video will help you understand: Object Oriented Design principles How to model entities like Issue, Agent, Transaction Using Strategy Pattern for issue assignment Extending the design for real-world systems 📊 UML + Code Walkthrough Included 💻 Language: Java (but can be implemented in any OOP language) 🔔 Don’t forget to Like, Share & Subscribe for more LLD, System Design & Machine Coding Interview Problems! #LLD #SystemDesign #PhonePe #MachineCoding #CustomerSupport #LowLevelDesign #Java #InterviewPrep #CodingInterview