Practice briefStart with your own approach
14. Sell a limited drop without overselling
Separate reservation, payment and confirmed purchase during a 50,000-person launch.
Product & backendMedium
Designs
Pick a system. Work through the problem. Compare your approach.
All designs 3
Ordered by design numberCompany tags are community-reported. Counts on cards show how many people reported that design.
TransactionsClear filters
30. Transactional Outbox
A service commits to its database and then publishes an event. If it dies in between, the row exists and no one hears about it. Publishing first has the mirror problem: an event for a write that never happened. There is no ordering of two independent systems that makes this safe.
Product & backendMedium51. Design a Local Delivery Service like Gopuff
Show what 10,000 small warehouses can deliver within the hour in under 100 ms, and take multi-item orders without ever selling a unit twice.
ClassicMedium