For Individuals
Free to start
- 3 new attempts monthly
- 20 published problems
- Upgrade for AI review
For Engineers
Practice system design. Get AI feedback that actually helps.
Work through 40 real-world problems, get an AI review, and unlock an ideal solution after you submit.
URL Shortener
EasyChat Application
MediumPayment System
HardSearch Engine
HardURL Shortener
EasyChat Application
MediumPayment System
HardSearch Engine
Hard40 real-world problems across 3 difficulty levels.
Practice Easy, Medium, and Hard prompts like URL Shortener, Chat Application, Payment System, and Search Engine.
7 / 10
Strong
BottlenecksTradeoffsReliabilityScale
Your design handled reads well, but needs a clearer cache invalidation strategy.
Know exactly where you stand.
See your score band from Developing to Expert, review 3-5 detected signals, and read a full written critique.
Your Design
Client
API
DB
Cache
Ideal Solution
✓ Complete Client
LB
API
Cache
DB
See how an expert would design it.
After submitting, unlock the ideal solution canvas and compare your choices side by side.
Two modes. Same canvas.
Practice mode lets you explore freely with no timer. Challenge mode adds interview pressure with timed attempts.