How would you design click tracking with a hard limit, in general?
Review note: The answer refers to the original author's CV or target job offer — adapt it to your own experience.
Answer out loud or in your head first, then compare.
Answer
This is a general design task, not a ready-made story about your implementation. First I establish what we count and what happens when the limit is exceeded. The decision “there's a spot and I'm taking it” has to be made in a way that doesn't let two requests use the last spot.
Configuration that tolerates delay can be cached, but a strict counter needs proper coordination. Reporting events can go to a queue with stable identifiers. I check what happens after a failure between taking the limit, adding the event and redirecting.
The choice of order has trade-offs: you can use up the limit without an event, or redirect without a report. You have to define the acceptable risk and how gaps get reconciled. The real variant of your project would be established by R01.
Why it matters: Lets you practise architecture without attributing it to your CV.
Possible follow-ups: What if the limit coordinator doesn't respond? How do you handle an exceptionally popular campaign?
How did it go? Be honest — “Not yet” puts the question on your review list.
Start with
- D-P15 · What is idempotency? — Backend, data and system design
- G-P01 · What is RAG? — RAG and retrieval
- H-P01 · How does an AI agent differ from a plain model call? — Agents and workflows
Further reading
- Cloudflare: Rules of Durable Objects(opens in a new tab)Page updated 18.10.2026. Per-entity coordination, storage, and care with interleaving around async I/O.
- Cloudflare Queues: Delivery guarantees(opens in a new tab)Docs; accessed 22.10.2026. At-least-once delivery and deduplicating side effects.