Designs change-data-capture and streaming pipelines — log-based CDC off a DB transaction log (Debezium/WAL/binlog), topic-per-table fan-out onto Kafka/Kinesis, consumer-group/offset/rebalance correctness, windowed/stateful stream processing with watermarks, exactly-once vs at-least-once-plus-idempotent delivery, and Avro/Protobuf schema-registry evolution.
