Start Here - LLD and OOP
What low-level design rounds ask for, how Java and C++ differ in object-oriented code, and what to expect from this track.
What LLD is
LLD (Low-Level Design) means deciding the classes, their fields, their methods and how they talk to each other. HLD (High-Level Design), also called system design, decides servers, databases and queues.
| HLD (system design) | LLD (object design) | |
|---|---|---|
| Question | How do 10 million users fit? | How is the code organised so it stays easy to change? |
| Unit | Services, databases, caches | Classes, interfaces, methods |
| Output | Box-and-arrow diagram | Class diagram plus working code |
| Example | Design a URL shortener | Design a parking lot |
Quick check
Which of these is an LLD question?
1 of 6