13 challenges from beginner to advanced

Ace your system
design interview

Practice on an interactive whiteboard, record your sessions, and compare your solution to expert answer keys. Built for engineers interviewing at top companies.

1 free beginner challenge — no credit card required

13 curated challenges

From beginner-friendly to the hardest questions asked at FAANG

Free
Beginner

Design a URL Shortener

HashingCachingDB
Free
Beginner

Design a Rate Limiter

RedisAlgorithms
Free
Beginner

Design Pastebin

Object StorageCDN
Moderate

Design Twitter's News Feed

Fan-outKafkaRedis
Moderate

Design Dropbox

SyncChunkingS3
Advanced

Design YouTube

Video ProcessingCDN
Advanced

Design Uber

GeospatialReal-time

Everything you need to prepare

A complete practice environment, not just flashcards

Interactive Canvas

Design systems on a Excalidraw-style infinite canvas. Draw components, arrows, and annotations just like a real whiteboard interview.

Session Recording

Record your practice sessions and review them later to spot gaps in your reasoning and improve your communication.

Expert Answer Keys

After your attempt, reveal a detailed answer key written by engineers who've passed interviews at Google, Meta, Amazon, and more.

Progressive Difficulty

Start with approachable beginner challenges, then level up to the complex distributed systems problems asked at top companies.

Simple pricing

Start free, upgrade when you're ready

Free

$0forever
  • 1 beginner challenge
  • Interactive Excalidraw canvas
  • Unlimited practice time
Get started free
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$9.99/month
  • All 17 challenges (moderate + advanced)
  • Session recording & playback
  • Expert answer keys for every challenge
  • Unlimited saved sessions
  • Cancel anytime
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Ready to level up your interviews?

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