2. The Medallion: Bronze, Silver, Gold

Three refinement tiers

Medallion architecture diagram: sources are ingested into Bronze (raw, append-only, immutable), cleaned and conformed into Silver, aggregated into Gold (business-ready), and served to dashboards and BI.
Data refined from raw sources to business-ready gold.
  • Bronze - raw, append-only, immutable. Every record is registered exactly as received: nothing lost, everything auditable.
  • Silver - cleaned and conformed: validated, de-duplicated, consistent schemas.
  • Gold - aggregated, business-ready: the tables that power dashboards and reporting.