Free
Backend·Storage
Design a URL shortener
Build a service that turns long links into short, shareable URLs.
Beginner 35 min
System design interview questions to practice.
Interview-grade design rounds for every discipline, each with a realistic brief, the scale to design for and a rubric-based review. Filter by level, time or topic, or search for a system, requirement or concept.
Plus
Backend·Messaging
Design a chat system
Create a real-time messaging experience for millions of people.
Intermediate 45 min
Plus
Backend·Data systems
Design a news feed
Deliver a relevant, fresh feed as people and publishers post.
Advanced 60 min
Plus
Backend·Storage
Design cloud file storage
Sync large files reliably across devices and collaborators.
Advanced 60 min
Plus
Backend·Reliability
Design an API rate limiter
Protect a public API without slowing down well-behaved clients.
Intermediate 40 min
Plus
Backend·Media
Design video streaming
Stream adaptive-quality video to a global audience.
Advanced 60 min
Plus
Backend·Geospatial
Design a ride-hailing service
Match riders with nearby drivers and track trips in real time.
Advanced 60 min
Plus
Backend·Transactions
Design a high-demand ticketing platform
Sell limited-inventory tickets fairly when a popular event goes on sale.
Advanced 60 min
Free
Backend·Messaging
Design a notification delivery service
Deliver timely, preference-aware messages across email, push, and SMS.
Intermediate 45 min
Plus
Backend·Search
Design a distributed web crawler
Discover and fetch public pages continuously while respecting site policies.
Advanced 60 min
Plus
Backend·Search
Design a search autocomplete service
Suggest useful completions quickly as users type into a search box.
Intermediate 40 min
Plus
Backend·Collaboration
Design a collaborative document editor
Let multiple people edit and comment on the same document in real time.
Advanced 60 min