Topic

Kafka & streaming

Ingestion that survives replay, late events, duplicate deliveries and producers you do not control. Kafka, Kinesis, Structured Streaming, CDC.

Streaming systems have to assume duplicates, late events, partial producer upgrades, and replays. I have built and operated ingestion and change-data-capture paths across several technologies, but the transferable lessons live above the brand names: idempotent writes, explicit event-time policy, backfills that do not double-count, schema compatibility, and a repair path that works while new traffic is still arriving.

All writing

Essay Reference systems, measured Measured on my own hardware

Exactly-once held through nine failures. The window counts did not.

Kafka, Flink, ClickHouse and Iceberg stayed exact through nine failures, yet 10-second window counts fell to 59.8% of on-time events. Why, and the fixes.

  • Kafka & streaming
  • Data quality & contracts
  • ClickHouse

13 min read