How should consumers handle duplicates?
Solution and explanation
- Be idempotent and record unique event IDs before side effects.
Which Kafka metrics matter?
Solution and explanation
- Lag, throughput, latency, ISR changes, offline partitions, resources and client errors.
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What is an under-replicated partition?
Solution and explanation
- A partition with fewer in-sync replicas than its replication factor.
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How do you secure Kafka?
Solution and explanation
- Use TLS, SASL, ACLs, private networking, secret management and audit logs.
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Design an e-commerce Kafka flow.
Solution and explanation
Commit the order and outbox, publish orders.created, then consume it independently downstream.Practice explaining this
Does Kafka deduct money?
Solution and explanation
- No; payment or core banking performs transactions and Kafka distributes events.
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Design a bank-transfer Kafka flow.
Solution and explanation
- The ledger and outbox commit atomically; Kafka feeds notification, fraud and audit.
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Which system owns financial balances?
Solution and explanation
- The authoritative transactional ledger, never Kafka alone.
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How do you combine durability settings?
Solution and explanation
- Use zone-aware replication, acks=all, suitable min ISR and safe elections.
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What makes production Kafka reliable?
Solution and explanation
- Idempotency, retries, DLTs, security, observability, capacity tests and recovery procedures.