Also ask questions

Never think your design is perfect

There are 4 Stages to the System Design Interview

Refine the requirements

This is the place to ask clarifying questions to the interview and gain a better understanding of the problem we’re trying to solve. Ask questions like:

• What is the expected user base?
• How many DAU do we expect?
• What are the core feature we are going to be working on? (If the task is broader and not a URL shortener)

Right down the answers in some notes and keep them in mind for the next steps

It’s key to do so, as we wanna design a system for which we understand the traffic we’ll be working with & the features we wanna design and scale.

High-Level Design

After coming to an agreement on the requiremenets it’s time to draw some components. Here you need to:

• Draw the core components in the system. Load Balancers, Service components, Caches, DBs..
• Make a rough estimation on the resources and speed we will need (back-of the envelop estimations)

Continue asking questions and having a discussion on whether each piece of the puzzle fits, with your interviewer!

• Don’t go into too much details here as we need to provide a basic understanding of the system. After that we can go into details