Top System Design Interview Questions: What You Need to Know

System design interviews can feel like a maze. I remember my early days, feeling overwhelmed by the sheer scope of possible questions. It felt like trying to hit a moving target, and I often left interviews feeling uncertain about my performance. Today, I want to share the key questions that consistently come up in system design interviews. If you’re gearing up for your next interview or just looking to sharpen your skills, this is for you. Let’s dive into the top system design questions and how to approach them, one by one.

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1. Designing a URL Shortener (Like TinyURL)

• The Question: How would you design a system that takes long URLs and shortens them?
• Why It Matters: Tests your ability to handle scale, hashing, and data storage.
• My Approach: Start with basic requirements, then dive into hashing algorithms, database choices, and potential bottlenecks.

Internal linking opportunity

If you want to get hands on practice, you may try Coudo AI's problems

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2. Building a Rate Limiter

• The Question: Design a rate limiter to prevent abuse on an API.
• Why It Matters: Shows your understanding of algorithms, concurrency, and distributed systems.
• My Approach: Discuss token bucket or leaky bucket algorithms, consider distributed rate limiting strategies, and talk about trade-offs.

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3. Designing a Social Media Feed

• The Question: How would you design the feed for a social media platform like Instagram?
• Why It Matters: Assesses your knowledge of data modeling, caching, and real-time updates.
• My Approach: Start with user stories, move to data models, discuss fan-out strategies, and address scalability challenges.

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4. Creating a Recommendation System

• The Question: Design a system to recommend products to users on an e-commerce site.
• Why It Matters: Tests your ability to apply machine learning concepts, data processing, and system optimization.
• My Approach: Outline collaborative filtering or content-based filtering, discuss feature engineering, and highlight the importance of A/B testing.

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5. Building a Chat Application

• The Question: Design a real-time chat application similar to WhatsApp.
• Why It Matters: Evaluates your understanding of messaging protocols, concurrency, and state management.
• My Approach: Talk about WebSocket vs. HTTP, discuss message queuing systems, and address scalability and reliability considerations.

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6. Designing a Search Autocomplete System

• The Question: How would you design a system that provides search suggestions as the user types?
• Why It Matters: Shows your knowledge of data structures, caching, and real-time retrieval.
• My Approach: Explain Trie data structure, discuss caching strategies, and address the need for low-latency responses.

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7. Building a Distributed Key-Value Store

• The Question: Design a distributed key-value store like Cassandra.
• Why It Matters: Tests your understanding of distributed systems, consistency models, and fault tolerance.
• My Approach: Discuss consistent hashing, replication strategies, and trade-offs between consistency and availability.

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8. Designing a Movie Ticket Booking System

• The Question: How would you design a movie ticket booking system like BookMyShow?
• Why It Matters: Assesses your ability to handle transactions, concurrency, and inventory management.
• My Approach: Start with use cases, move to database design, discuss seat reservation strategies, and address payment processing.

Internal linking opportunity

If you want to get hands on practice, you may try Coudo AI's problems

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9. Designing a Ride-Sharing App

• The Question: Design a ride-sharing application similar to Uber or Ola.
• Why It Matters: Evaluates your knowledge of location-based services, real-time updates, and matching algorithms.
• My Approach: Discuss geospatial indexing, real-time tracking, and matching algorithms, and address scalability challenges.

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10. Designing an Expense Sharing Application

• The Question: How would you design an expense sharing application like Splitwise?
• Why It Matters: Tests your understanding of data modeling, graph databases, and transaction management.
• My Approach: Start with user stories, move to data models, discuss graph databases, and address transaction management.

Internal linking opportunity

If you want to get hands on practice, you may try Coudo AI's problems

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FAQs

Q1: How do I prepare for system design interviews?
Start by understanding the fundamental concepts.
Practice with sample problems and case studies.
Coudo AI offers problems that can help you gain real-world experience.

Q2: What's the best way to approach a system design question?
Start by clarifying requirements.
Break down the problem into smaller parts.
Communicate your thought process clearly.

Q3: How important is scalability in system design interviews?
Very important.
Scalability is a key consideration in most system design questions.
Always think about how your design will handle growth.

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Wrapping Up

I hope my list of top system design interview questions helps you prepare better. It took me time to learn what works and what doesn’t in system design interviews. If you want to deepen your understanding, check out more practice problems and guides on Coudo AI. Remember, continuous improvement is the key to mastering system design interviews. Good luck, and keep pushing forward!