Cianplan

Level 6: Applied: cases, FDE scenarios, mocks · L6.1 Classic cases I

Notification system

Design multi-channel notifications with retries and dedup.

15 min · Pro

What you take away

  • The burst is the design driver: 1M messages in five minutes is 30× average, and a provider that accepts 200/s takes 83 minutes to drain it.

And 3 more inside the class, in Pro.

How the class is laid out

  1. The prompt
  2. Requirements and the numbers that matter
  3. The design
  4. Three decisions
  5. The method
  6. URL shortener
  7. Rate limiter
  8. Unique IDs
  9. Key-value store
  10. Notifications
  11. Check your understanding