Stream Processing Engines

A practical example

Example: a prospect visits the pricing page twice, then starts a trial. The stream engine correlates the three events in seconds and pushes the account into a high-intent queue for same-day outreach.

What to evaluate before investing

• Ask how the engine handles out-of-order and late-arriving events, since real traffic rarely arrives in sequence.
• Check state management: how long event history is retained in memory or storage, and what it costs at your event volume.
• Verify how the engine connects to your trigger tools, such as whether it can call a webhook or write to a queue your automation reads.

Limitations and tradeoffs

Streaming adds constant infrastructure cost and operational complexity; for many marketing use cases, minute-level batch processing is cheaper and sufficient.