Your system design path
One step at a time. Learn the concept, build it and prove it under failure.
Core path5 stages · 19 systems
Go from “I know the basics” to designing systems that survive reality.
Each stage adds one new layer: scale, asynchronous work, correctness, then global traffic. Follow the order or explore at your own pace.
0 of 19 systems mastered0%
Start: URL ShortenerYour next recommended challenge. No decision fatigue.
Need the foundations first?
Take the 9 free System Design 101 lessons. No account required.
Your first systems
Free stageCurrent stageBuild the three core shapes every backend developer should know.
Scale a backend
ProTurn a working service into one that survives growth and failure.
Async & real-time
ProMove work off the request path and keep users connected live.
Data & correctness
ProProtect invariants when money, inventory and concurrency collide.
Planet-scale systems
ProCombine every trade-off in systems with global traffic and state.