Learn Use Case Diagrams — a key concept for LLD interviews.
Interactive — Try it yourself!
How to use
1See 3 actors: User, Admin, System (stickfigures)
2Click an actor to highlight their use cases (ovals)
3User: Borrow Book, Return Book, Search. Admin: Add Book
4Lines connect actors to the use cases they can perform
In a nutshell
Use case diagrams show WHAT a system does from the user's perspective. Actors (who) connected to use cases (what). Great for initial requirements gathering in interviews.