15 Golden System Design Interview Tips
When I started preparing for system design interviews for the first time in 2019, I felt completely overwhelmed. It wasn’t a subject covered in college, and I had no prior experience building scalable systems.
But, over time, I realized that you don’t need professional experience with distributed systems to pass system design interviews.
Even experienced engineers often find these interviews challenging because the format is unique and requires a specific approach.
The good news is that once you understand the basic concepts, the building blocks, and trade-offs, and learn how to connect them effectively, system design interviews become far less intimidating.
In this article, I’ll share 15 tips that improved my system design interview skills and made it significantly easier—and hopefully, they’ll do the same for you.
1. What Interviewers Want to See
In a system design interview, the interviewer evaluates your ability to think critically, design effectively, and communicate clearly.
Here’s what they are looking for:
- Clarify Requirements: Can you ask the right questions to clarify functional and non-functional requirements?
- System Architecture: Can you outline the main components of the system (e.g., clients, APIs, databases, caching, load balancers) and explain how they interact?
- Scalability: Can your design handle increased traffic or scale with user growth?
- Fault Tolerance: Can you address single points of failure and ensure fault tolerance?
- Trade-Offs: Can you explain the pros and cons of your decisions and justify your choices?
- Detailing Components: Can you dive into the details of critical components (e.g., database schema, caching strategy, API design)?
- Bottlenecks and Edge Cases: Can you identify potential issues and propose strategies to mitigate them?
- Clear Communication: Can you articulate your ideas clearly and engage in a constructive discussion with the interviewer?
- Adaptability: Are you receptive to feedback and able to refine your design?
- Time Management: Can you manage your time effectively and focus on high-impact components?
- Patterns: Are you familiar with common system design patterns (e.g., sharding, replication, caching)?
- Tools: Can you discuss tools or technologies relevant to the problem?