Explain Kafka architecture and reliability semantics
Company: TikTok
Role: Software Engineer
Category: System Design
Difficulty: hard
Interview Round: Technical Screen
Explain Kafka’s architecture: topics, partitions, leaders/followers, replication factor, and in-sync replicas. Describe how producers choose partitions and configure acknowledgments. Explain how consumer groups commit offsets and handle rebalances. Discuss ordering, idempotence, and exactly-once processing. Outline backpressure strategies, batch sizing, compression, and throughput tuning. Describe designing end-to-end at-least-once versus exactly-once semantics.
Quick Answer: This question evaluates understanding of Kafka architecture and reliability semantics, covering topics such as topics and partitions, replication and ISRs, producer and consumer behaviors, delivery guarantees, and performance tuning for streaming systems.