5 Best Tools to Practice System Design Interviews in 2025
System design interviews are one of the most important (and often most intimidating) parts of the hiring process at companies like Google, Meta, Amazon, and Netflix. Unlike coding rounds, there’s no single right answer — you’re judged on how you think, communicate, and design scalable systems.
Here are 5 of the best tools in 2025 to help you practice and prepare with confidence.
System Design GPT
A conversational GPT trained to simulate real system design interviews. It walks you through prompts, follows up with clarifying questions, and helps you structure your answers.
Example prompts:
Design a chat app like WhatsApp
SQL vs NoSQL trade-offs
Build a ride-sharing platform like Uber
Excalidraw
A minimalist whiteboarding tool ideal for sketching out system components, data flow, and scaling diagrams. It’s especially helpful for remote interviews or solo practice. Pair it with a list of system design questions to simulate the full interview process.
Grokking the System Design Interview
A paid course that breaks down common system design problems using reusable templates. It’s structured, beginner-friendly, and widely recommended by engineers who’ve succeeded at top tech companies.
ByteByteGo (YouTube + Book)
Created by the author of the System Design Interview book series, ByteByteGo is packed with real-world examples and clean visuals. Great for understanding how large-scale systems actually work.
Interviewing.io
When you're ready to test yourself, this platform lets you do mock system design interviews with engineers from top companies. It’s anonymous, realistic, and includes actionable feedback.
Use the Right Tools — and Know Where to Apply
System design interviews require more than just practice — they require structure and feedback.
And when you're ready to apply for real, don't forget:
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