Watermarks

Illustration of a data stream with timestamps and a watermark line.

Where Stream Processing Systems Draw the Line for Late Data

A deep dive into how stream engines decide what counts as late data, the mechanisms they expose, and best‑practice patterns for robust pipelines.

Illustration of a flowing data stream with timestamp markers.

How Stream Watermarks Define Event Time Progress

Watermarks are the backbone of event‑time handling in modern stream processors. This post explains their purpose, generation, and impact on windowing.

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