The product owner of fictional Clover Links needs create, redirect and expiry for event URLs. Use 21,600,000 redirects/day, an eightfold peak and three API replicas. Deliver a board, API contract, keyed mapping table and collision policy. Analytics and custom domains are excluded.
Clover Links is a fictional link service for a neighborhood events publisher. Its product owner wants short links that expire after an event. The redirect workload is much larger than the creation workload, so the read path deserves attention. You will build one design in six steps, keeping your earlier work as you add requirements.
The design needs a durable mapping and a unique code. Random generation can collide, so explain the insertion behavior as well as the happy path. Expired rows may remain in storage until cleanup; the service must enforce logical expiry when it reads them. Cache freshness and expiry checks still matter even when the cache hit rate is high. Your final board, API and data model form the deliverable.