Path 2 · Streaming Mastery

~1 hour. Windows, keyed state, joins — deterministic stream processing without writing state code.

1. Windows & aggregations — sliding windows, keyed state, the aggregator palette.
2. Stream-stream joins — order meets shipment — correlate two flows; the misses are the alerts.
3. Keyed timers — detect the silence — turn the absence of events into an event.
4. Multi-topic union — merge the flows — fan-in with one line of config.

Where you land: you can shape any raw stream into clean, enriched, per-key signals — the input every good detector and every affordable LLM stage depends on.