# System design interview

A system design interview asks a candidate to architect a large-scale software system, such as a URL shortener, a news feed, or a chat application, by discussing trade-offs in scalability, data storage, APIs, and reliability rather than writing implementation code.

It's a conversation and a whiteboard-style diagram, not a coding exercise.

**System design interview** — A system design interview asks a candidate to architect a large-scale software system by discussing trade-offs in scalability, data storage, APIs, and reliability, rather than writing implementation code. The problem is deliberately open-ended, and part of what's being evaluated is whether the candidate asks the right clarifying questions before settling on a solution.

The format is standard for senior and staff-level engineering roles at companies operating at real scale, where reasoning about millions of users, distributed systems, and failure modes matters more than any single algorithm. A typical session has the candidate sketch an architecture, then defend specific decisions when pushed: why a particular database, how the system handles a traffic spike, what happens when one component fails. There's rarely a single correct answer; interviewers evaluate the reasoning behind each trade-off.

## Frequently asked questions

### Do you need to write code in a system design interview?

Generally no. The focus is on architecture and trade-offs at a high level, expressed through diagrams and discussion, rather than implementation code. Some interviewers may ask for pseudocode on a specific piece, but it's not the core of the exercise.

### What topics come up most in system design interviews?

Common topics include load balancing, database choice and sharding, caching, API design, and how a system handles failure or scale. The mix depends on the company and the system being discussed.

### How is a system design interview different from a technical interview?

System design interviews are a specific type of technical interview focused on architecture at scale. A general technical interview can also include coding exercises or role-specific tool knowledge that a design round doesn't cover.

## Related pages

- [Browse open roles](/jobs)

## Get comfortable narrating trade-offs

Practicing how you explain technical reasoning out loud, in an Intervieux AI interview, carries directly into a system design round.

Start practicing free: https://www.intervieux.ai/register · Hire with Intervieux: https://www.intervieux.ai/employers/signup