Avoiding Common Pitfalls in System Design Interviews

Avoiding Common Pitfalls in System Design Interviews

March 12, 2023

Moch Lutfi
Moch Lutfi

System design interviews are a critical part of the technical interview process for software engineers. These interviews assess a candidate's ability to design scalable and efficient systems that meet specific requirements. However, many candidates fall into common pitfalls that can hurt their performance in these interviews. In this article, we will discuss some of these common pitfalls and how to avoid them. If you never read my previous post related how to do system design interview, you must read it first.

Not Understanding the Problem Statement

One of the most common pitfalls is not fully understanding the problem statement. To avoid this, take the time to read and re-read the problem statement. Ask clarifying questions if necessary, and make sure you understand the constraints and requirements. Breaking down the problem into smaller components can also help you better understand the problem and design a more efficient system.


  • Don't go into detail prematurely

Overcomplicating the Design

Another common pitfall is overcomplicating the design. While it's important to have a scalable and efficient design, overcomplicating the design can make it difficult to understand and maintain. Keep things simple and easy to understand. Don't add unnecessary complexity that can lead to bugs or performance issues.

Ignoring Trade-Offs

Every design decision comes with trade-offs. It's important to consider these trade-offs and explain your reasoning for the decisions you make. For example, you may need to choose between speed and scalability, or between complexity and maintainability. Be sure to communicate your thought process and the trade-offs you considered.

Not Considering Edge Cases

Edge cases and corner cases can have a significant impact on the behavior of a system. Failing to consider these cases can lead to unexpected behavior and bugs. Think through edge cases and consider how the system will behave under unusual or unexpected circumstances.

Ignoring Feedback

Interviewers may provide feedback or ask follow-up questions throughout the interview. Ignoring this feedback can hurt your performance. Listen to the interviewer's feedback and adjust your design as needed. Be open to suggestions and willing to make changes based on feedback.

Not Prioritizing Requirements

It's important to prioritize the requirements of the system based on the problem statement. Focus on the most critical requirements and ensure your design meets those requirements. Failing to prioritize requirements can lead to an inefficient and ineffective design.

Failing to Communicate Your Thought Process

Communication is key in a system design interview. Make sure you communicate your thought process clearly and explain your design decisions. Articulate your reasoning and thought process in a clear and concise manner. This will help the interviewer understand your design and the decisions you made.


System design interviews can be challenging, but avoiding these common pitfalls can help you perform better. Take the time to understand the problem statement, keep your design simple and easy to understand, consider trade-offs and edge cases, listen to feedback, prioritize requirements, and communicate your thought process clearly. By avoiding these common pitfalls, you can design an efficient and effective system and impress your interviewer.