Flows
Architecture notes and flow breakdowns for real product behavior.
A real booking-slot design: timed holds, row locks, Paytm payment attempts, webhooks, retries, refunds, and double-booking protection.
A gateway-first backend design: request identity, JWT/API key validation, Redis token buckets, atomic quota checks, service routing, 429 rejection, and abuse visibility.
A background-work design: durable job records, queue publishing, worker leases, idempotent handlers, bounded retries, dead-letter replay, and operational visibility.
A TinyURL-style design: Base62 short-code allocation, custom aliases, cache-first redirects, expiration, abuse checks, async analytics, sharding, and hot-link reliability.
More system cases coming soon.