Design LinkedIn
| Difficulty: Medium | Source: awesome-low-level-design |
Requirements
- User registration and authentication
- Profiles with picture, headline, summary, experience, education, skills
- Connection requests (send, accept, decline)
- Messaging between connections
- Job postings by employers
- Search for users, companies, jobs
- Notifications (real-time)
- Scalable for large concurrent users
Class Diagram
Classes, Interfaces and Enumerations
| Class/Interface | Description |
|---|---|
| User | id, name, email, password, profile, connections, messages |
| Profile | picture, headline, summary, experiences, educations, skills |
| Experience | Profile component for work history |
| Education | Profile component for educational background |
| Skill | Profile component for skills |
| Connection | connected user, date |
| Message | id, sender, receiver, content, timestamp |
| JobPosting | id, title, description, requirements, location, date |
| Notification | id, user, type, content, timestamp |
| NotificationType | Enum: connection request, message, job posting |
| LinkedInService | Singleton; ConcurrentHashMap + CopyOnWriteArrayList for thread-safe management |
Design Patterns Used
| Pattern | Application |
|---|---|
| Singleton | LinkedInService has a single instance managing the entire platform |
Code Implementations
| Language | Source Code |
|---|---|
| Java | View on GitHub |
| Python | View on GitHub |
| C++ | View on GitHub |
| C# | View on GitHub |
| Go | View on GitHub |