3.4. Ingest and Transform Streaming Data

💡 First Principle: Streaming processing addresses the "velocity" of data, moving from periodic batch updates to continuous, real-time insights. Unlike batch where you can wait, collect, and process, streaming requires handling data as it arrives—with all the complexity of late events, out-of-order data, and unbounded datasets.

What breaks without proper streaming architecture? Consider an e-commerce fraud detection system. Batch processing that runs hourly means fraudulent transactions complete before you detect them. Streaming processes transactions in milliseconds, enabling real-time blocking.