1. Choose ETL or ELT from the workload
Both designs preserve raw evidence. ETL prepares before the analytical target; ELT loads raw/staged data then transforms within the target. Technical architecture does not decide whether a source value is authoritative.

2. Implement ingestion, transformation and validation
All 48 fixture lines pass technical validation; 42 belong to completed orders and sum to 119000 cents. Six cancelled-order lines are valid source records outside reporting scope, not quality rejections.

3. Define publication and failure boundaries
A duplicate order key raises an error and must not produce accepted downstream data. A partial directory without a valid final manifest is not a successful run. Atomic publication and concurrent-run control remain explicit production design tasks.
