Kafka for Software Engineers

Kafka is often described as a message broker, an event bus, or a streaming platform. Those descriptions are not wrong, but they can be misleading if they make it sound like Kafka is just another queue with more knobs. The most useful way to understand Kafka is this: Kafka is a durable, distributed log that many producers can append to and many consumers can read from at their own pace. A lot of its design starts making sense once you focus on the log part. If you have only built request-response systems, Kafka can feel unfamiliar at first. In a typical HTTP setup, one service calls another service directly and waits for an answer. That works well for many problems, but it creates tight coupling in time and availability. The caller has to know who to call, the callee has to be up, and the two sides need to agree on how fast the interaction should happen. Kafka solves a different kind of problem. It helps when systems need to exchange facts about things that happened, without every produ