Code Room
System designHard
Question
Design the inventory system for an e-commerce site that must prevent overselling during a flash sale where thousands try to buy the last few units simultaneously.
What a strong answer looks like
Clarify scale and constraints first. Propose a clean component breakdown, then go deep on the hard parts — data model, bottlenecks, consistency, failure modes — and name the trade-offs you are making.
Learn the concepts
Loading whiteboard…
Run or narrate your approach, then ask the coach.