LLD interview expectations - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does LLD stand for in system design interviews?

LLD stands for Low-Level Design. It focuses on designing the internal structure and components of a system or module.

beginner

Name three key elements interviewers expect in an LLD interview.

1. Clear class and object design<br>2. Proper use of design patterns<br>3. Handling of edge cases and scalability

intermediate

Why is it important to discuss design patterns during an LLD interview?

Design patterns provide reusable solutions to common problems. Discussing them shows understanding of best practices and clean design.

intermediate

What role does UML play in LLD interviews?

UML diagrams help visually communicate the design. They clarify relationships between classes and components for better understanding.

advanced

How should you handle scalability concerns in an LLD interview?

Explain how your design can handle growth, such as adding new features, managing more users, or improving performance.

What is the main focus of an LLD interview?

A Estimating system capacity

B Choosing cloud providers

C Designing detailed classes and methods

D Writing SQL queries

LLD interviews focus on detailed design of classes, methods, and interactions.

Which diagram is commonly used to represent class relationships in LLD?

A Sequence Diagram

B Class Diagram

C Use Case Diagram

D Deployment Diagram

Class diagrams show classes and their relationships, essential for LLD.

Why should you discuss edge cases in an LLD interview?

A To show you can handle unexpected situations

B To increase code length

C To avoid writing tests

D To impress with complex code

Discussing edge cases shows thoroughness and robustness in design.

Which design pattern is useful for creating objects without specifying exact classes?

A Decorator

B Singleton

C Observer

D Factory

Factory pattern helps create objects without exposing the creation logic.

What should you do if you realize your initial design is too complex during the interview?

A Explain and simplify it step-by-step

B Ignore and continue

C Start over without explanation

D Add more classes to fix it

Explaining and simplifying shows problem-solving and communication skills.

Describe the key steps you would take to prepare for an LLD interview.

Think about how you break down a problem into smaller parts.

Explain how you would communicate your design clearly during an LLD interview.

Imagine teaching your design to a friend.