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  • Ashish Kaushal thinks this is interesting:

The consumer subscribes to one or more topics and reads the messages in the order in which they were produced


Cover of Kafka: The Definitive Guide


But message order can't be guaranteed across a topic but across a partition. Since message can be send to multiple partitions therefore message offset on a slower partition can be 10 and on faster partition can be 12. A consumer that round robins between partitions can consume message 12 before message 10