What Rebuilding Kafka From Scratch Actually Teaches You There's a gap between using a system and understanding it. Most engineers never close that gap, and honestly, most of the time that's fine. Kafka works. Topics, producers, consumers, pull the levers, ship the data. Done. But then you hit a weird latency spike, or a consumer group stalls in a way that doesn't match the docs, or replication starts behaving like it has feelings. And suddenly "I know the terminology" doesn't cut it a...