Arslan Ahmad

December 24th, 2024

How to Approach Any System Design Question in a Tech Interview

Learn the art of answering any system design interview question efficiently

System design interviews are no longer reserved for senior roles. They’re becoming a must-have skill, even for entry-level candidates at top companies like Google, Amazon, and Meta.

Do you know why?

Because understanding how systems are built—and rebuilt—is now as important as coding itself.

Even if you're a coding expert, going blank on system design questions means you need to work on them. And passing this round of the interview is essential to getting into any top tech company.

To help you understand the process of answering system design questions, we have compiled this guide covering everything that is needed.

Let us discuss the simple and practical approach to answering any system design interview question.

What is a System Design Question?

A system design question asks you to design a complex software system—think of services like Instagram, Uber, or Dropbox.

These questions evaluate your ability to:

Break down large problems into smaller components
Build scalable, efficient, and reliable systems
Navigate trade-offs in technology choices

Check out the complete System Design Interview guide.

Step 1: Clarify the Requirements

When you’re asked a system design question, don’t jump straight into solutions. First, clarify the requirements:

What is the goal? Is it scalability, performance, or reliability?
Who are the users? Are we building for millions of global users or a niche audience?
What features are needed? Login, search, real-time updates?

For example, if the question is about designing a URL shortening service like TinyURL, ask: “Should it handle millions of requests per second?” or “Do we need analytics for shortened links?”

Always confirm these requirements with the interviewer.

Check out What Questions Are Asked in a System Design Interview to prepare more effectively.

Step 2: Define the Scope

System design questions are broad by nature.

Therefore, it is better to narrow the scope to focus on the most critical aspects.

For instance, if you’re tasked with designing an e-commerce website, prioritize user search, product listings, and payment processing over analytics or inventory management.

Need help defining scope?

Explore What is System Design Specification for more insights.

Step 3: Create a High-Level Design

Start with a high-level overview. Try to use simple building blocks and explain how they interact.

For example:

Clients: Mobile and web apps
Backend Services: APIs and servers
Databases: For user data, product details, or posts

Sketch a diagram (even on paper) and explain it. This shows clarity and structured thinking.

For a better understanding of common patterns, read What Are the 4 Types of System Design.

Step 4: Cover Key Components

Zoom in on the most critical parts of the system. For example:

Scaling: Use load balancers and database sharding
Performance: Add caching with tools like Redis or Memcached
Reliability: Implement data replication and backups

Discuss trade-offs in your choices, like cost versus performance.

For inspiration, explore Top Must-Know Design Patterns.

Step 5: Address Trade-Offs and Scalability

Every design decision involves trade-offs. Show your ability to weigh options by explaining choices like:

SQL vs. NoSQL databases
Consistency vs. availability

Additionally, discuss how your design scales to handle growth. Highlight features like horizontal scaling, caching layers, and monitoring tools.

For more details, check out SOLID Design Principles.

Step 6: Iterate and Refine

Your first design isn’t your final answer. Therefore, be open to feedback and suggestions from the interviewer.

Also, try to adapt and refine your approach based on their input. This shows collaboration and problem-solving skills.

Step 7: Practice Common Questions

Practice makes perfect. And it is the best way to improve any skill.

You can start with common system design challenges like:

Design a URL shortening service [Watch Tutorial]
Design a chat application like Messenger [Watch Tutorial]
Design Instagram [Watch Tutorial]
Design a ride-sharing service like Uber

Learn the art of answering any system design interview question.

For tailored preparation, check out Grokking the System Design Interview.

Final Words

Approaching system design questions isn’t just about knowledge; it’s about structure, communication, and practice.

Follow this guide, practice as much as you can, and use the right resources to master system design questions in tech interviews.

FAQs

For more tips, revisit What Questions Are Asked in a System Design Interview.

System Design Interview