What is source system latency?

< 1 min read

Source system latency is the delay between a business event happening and it becoming available in the source database for extraction.
For example, when a customer places an order, the application may take a few minutes to commit and finalize the record.
In one project, payment confirmations appeared 5–10 minutes late due to external gateway processing.
So even if our ETL ran every 10 minutes, reports still looked delayed.
We adjusted dashboard expectations and added a “data updated as of” timestamp.
We also scheduled extraction slightly after peak transaction windows to capture stable data.
This helped avoid partial or missing records in hourly reports.
Understanding latency prevented stakeholders from assuming the dashboard was broken.
It’s important when defining SLAs for near real-time reporting.

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