Api-backend

The point where synchronous request-response stops being enough, and the honest case for a message broker like Kafka. The good reasons are decoupling, load-leveling, fan-out, and durability. The bill is eventual consistency, added latency, operational burden, and harder debugging. And a clear account of when you should not reach for it at all.

The honest defense of synchronous request-response. Before reaching for a broker, most systems have a long runway left in boring, well-understood techniques: stateless services, connection pooling, caching in front of the database, and read replicas. Services scale for free. The database is the ceiling. Knowing how far sync goes tells you when you actually need something else.