Welcome to the LLD Solutions Repository!
This repository contains detailed solutions to common Low-Level Design (LLD) interview questions. Whether you're preparing for system design interviews or want to strengthen your object-oriented design skills, this repo is for you.
Each solution includes:
- ✅ Problem Statement
- 🏗️ Design Approach
- 🔁 Class Diagrams (where applicable)
- 🧱 Object-Oriented Code (in Java/Python/C++/... as applicable)
- 🧪 Sample Use Cases / Unit Tests
| # | Problem | Status | Language |
|---|---|---|---|
| 1 | Design a Parking Lot | ✅ Completed | Java |
| 2 | Design a Tic-Tac-Toe Game | ✅ Completed | Python |
| 3 | Design a Splitwise System | ✅ Completed | Java |
| 4 | Design a Library Management System | 🚧 In Progress | Python |
| 5 | Design a Movie Ticket Booking System | ✅ Completed | Java |
| 6 | Design an Elevator System | ✅ Completed | C++ |
ℹ️ More problems will be added soon. Contributions welcome!
- 💻 Programming Languages: Java, Python, C++
- 🧪 Unit Testing: JUnit, PyTest
- 🧰 Tools: UML diagrams (draw.io), Markdown
Contributions are welcome! Feel free to:
- Add new LLD problems with solutions
- Improve existing designs
- Suggest improvements or optimizations
- Fork the repository
- Create a new branch:
git checkout -b feature/my-new-problem - Commit your changes
- Push to the branch:
git push origin feature/my-new-problem - Submit a Pull Request
This project is licensed under the MIT License.
This repository was inspired by countless design interviews and system design discussions in the tech community.
Have questions, feedback, or suggestions?
Open an issue or reach out via email at your.email@example.com.