Asked about Moving data reliably

How do you make a data pipeline safe to rerun?

An answer that works

Idempotency: write to a partition keyed by the period being processed and replace it rather than appending, so a rerun produces the same result. Parameterise by date range so backfills use the same code path.

Reading an answer is not being able to give one. The section that teaches this is Moving data reliably, 5 hours of Data pipelines.

Learn this properly