🪵 Kafka

Sending a message to Kafka looks like one line of code, and most of us treat what happens next as a black box. That’s fine until you need to know when a message is really safe, or why sending in batches is faster. This article follows a message from the producer to the files on the broker’s disk: batching, an append-only log split into segments, and how the broker detects half-written data after a crash. It’s long and detailed, with code.