How would you implement logic for three ordered tiers (Bronze, Silver, Gold) in a target table?

To implement logic for Bronze, Silver, and Gold tiers, first define the business rules that determine which records belong to each tier. In a typical ETL pipeline, the Bronze layer contains raw, ingested data. The Silver layer cleanses and enriches this data, applying transformations such as null handling, type casting, and basic aggregations. The Gold layer delivers business‑ready data, often denormalized and aggregated for reporting.

Implementation steps:

1. Bronze: Load raw data into a staging table. Store metadata (source, load timestamp) for audit.
2. Silver: Create a transformation job that reads from Bronze, applies data quality checks (e.g., schema validation, duplicate removal), and writes to a Silver table. Use incremental loads by tracking last processed timestamp.
3. Gold: Build a business‑logic layer that aggregates Silver data into fact and dimension tables. Apply final transformations such as currency conversion, KPI calculations, and denormalization.

Use a workflow orchestrator (Airflow, Prefect, or native cloud services) to schedule these jobs and enforce dependencies. Store lineage metadata so you can trace a record from Bronze to Gold. This layered approach ensures data quality, traceability, and performance optimization at each stage.