Skip to main content
System design is a very extensive topic and system design interviews are designed to evaluate your capability to produce technical solutions to abstract problems. Unlike traditional coding interviews, they’re not designed for a specific answer. The unique aspect of system design interviews is the two-way nature between the candidate and the interviewer.

​
What makes system design interviews unique?

System design interviews differ from other technical interviews in several important ways:
  • Two-way dialogue: These interviews are collaborative discussions rather than one-sided problem solving. You’re expected to ask questions, clarify requirements, and discuss trade-offs with the interviewer.
  • No single correct answer: Unlike coding problems with specific solutions, system design questions have multiple valid approaches. Your thought process and reasoning matter more than reaching a particular design.
  • Abstract and vague: By nature, system design questions are intentionally broad. This tests your ability to narrow down requirements and handle ambiguity.
  • Level-dependent expectations: The expectations vary significantly based on your experience level. Someone with extensive practical experience will approach these problems quite differently from someone new to the industry.

​
Different expectations at different levels

Expectations are quite different at different engineering levels:
  • Junior engineers: Expected to understand basic concepts, ask clarifying questions, and demonstrate foundational knowledge of system components.
  • Mid-level engineers: Should show deeper technical understanding, consider trade-offs, and propose practical solutions with awareness of scalability concerns.
  • Senior engineers: Expected to drive the discussion, consider business implications, demonstrate experience with real-world systems, and proactively identify and resolve potential issues.
As a result of these varying expectations, it’s hard to come up with a single strategy that will help everyone stay organized during the interview. Adapt your approach based on your experience level.

​
What interviewers are evaluating

During a system design interview, interviewers assess:
  • Your ability to handle ambiguity and ask the right questions
  • Technical knowledge of system components and architecture patterns
  • Understanding of trade-offs between different approaches
  • Communication skills and ability to explain complex concepts
  • Problem-solving approach and structured thinking
  • Practical experience and real-world awareness
Before your interview, read the engineering blog of the company you’re interviewing with. This will help you get a sense of what technology stack they’re using and which problems are important to them.

​
Common mistakes to avoid

Here are some pitfalls to watch out for:
  • Jumping to solutions too quickly: Don’t start designing before understanding requirements
  • Being too opinionated: Statements like “NoSQL databases are just better, SQL databases are not scalable” reflect poorly
  • Not asking questions: Failing to clarify requirements shows poor communication
  • Ignoring constraints: Not considering scale, budget, or real-world limitations
  • Lack of trade-off discussion: Not explaining why you chose one approach over another
Be humble about what you know and what you don’t. Use your existing knowledge with examples to navigate the interview, but acknowledge when you’re uncertain about something.

Build docs developers (and LLMs) love

Get started for freeTalk to us