This article was first published on the Bruin blog .

Quick answer: CDC stands for change data capture . It is a way to track inserts, updates, and deletes in a source system, then move those changes into another system without reloading the whole table every time.

The shortest version:

source database changes -> CDC process -> warehouse, lake, stream, or another database

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If an order is inserted in Postgres, CDC can send that new order to BigQuery. If a customer row is updated in MySQL, CDC can send the updated version to Snowflake. If an account is deleted in SQL Server, CDC can preserve that delete as an event so the destination does not quietly drift away from the source.

That's the useful bit. CDC is not just "faster ETL". It changes the shape of the ingestion problem: instead of asking "what does the full table look like now?", you ask "what changed since the last point I safely processed?"

This article covers the broader capture method.…