Kafka is powerful but has common pitfalls — misunderstandings and mistakes around partitioning, ordering, consumer behavior, delivery semantics, and operations. Understanding these helps avoid problems and use Kafka correctly.
Design and partitioning pitfalls
✗ Too FEW partitions → limits consumer parallelism (can't scale consumption beyond
partition count); too MANY → overhead, rebalancing pain → plan partition count carefully
✗ Wrong PARTITION KEY → uneven distribution (hot partitions) or wrong ordering scope →
choose a key for even distribution AND the ordering you need
✗ Expecting GLOBAL ordering → Kafka only orders WITHIN a partition (a common misunderstanding)
✗ Adding partitions changes key→partition mapping → breaks ordering for keys (be careful)
