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Diagram Microsoft Fabric

Medallion Architecture Visual Guide

Bronze, Silver and Gold on one page: what each layer is for, what belongs in it, and when fewer layers are enough.

Type
Diagram
Level
Beginner
Format
Printable

In short

Each Medallion layer has a different responsibility: Bronze keeps what arrived, Silver makes it trustworthy, Gold shapes it for a business use. Add a layer only when it has a job and an owner.

Who it is for

  • Engineers designing or reviewing a Lakehouse platform
  • Students learning how data moves from sources to reports

What it helps you do

  • Explain what each layer is responsible for
  • Decide where a transformation belongs
  • Recognise when three layers are more than the workload needs
On this page
  1. The flow
  2. What each layer is for
  3. Where does this belong?
  4. Do you always need three layers?
  5. Quick checks

The flow

  1. SourcesApplications, files, APIs, databases
  2. BronzeLand the data as received
  3. SilverClean, validate, conform
  4. GoldShape for a business use
  5. ConsumersReports, models, APIs
Data moves from sources through Bronze, Silver and Gold to the people and systems that use it. Each step adds trust or business shape.

What each layer is for

  • Bronze

    Keep what arrived

    • Raw
    • Auditable
    • Source-aligned
    • Minimal transformation

    Can I replay or audit what the source sent?

  • Silver

    Make it trustworthy

    • Clean
    • Validated
    • Deduplicated
    • Conformed

    Can other teams build on this data?

  • Gold

    Shape it for a use

    • Business-ready
    • Aggregated
    • Reporting and API serving

    Does this answer a business question directly?

The responsibility of each layer. A table belongs in the layer whose job it does.

Where does this belong?

If the step… Put it in
lands files or rows exactly as the source sent them, with load metadata Bronze
fixes types, removes duplicates, applies validation rules or joins reference data Silver
aggregates, applies business definitions or shapes tables for a report, model or API Gold
only renames columns for one report Gold, or the semantic model

Do you always need three layers?

No. The number of layers should follow the workload, not the pattern’s name.

  • Simple

    One source, one consumer, little cleaning

    1. Source
    2. Curated
    3. Consumer

    Use when there is nothing to replay and one team owns the whole flow.

  • Complex

    Many sources, shared data, audit needs

    1. Source
    2. Bronze
    3. Silver
    4. Gold
    5. Consumer

    Use when sources must be replayed, many teams reuse cleaned data, or audits need the raw history.

A simple workload can go straight from source to a curated layer. Add Bronze and Silver when replay, auditing or shared, conformed data justify them.

Quick checks

  • Every layer has a stated purpose and an owner.
  • Bronze can be rebuilt from, or replayed to, the source.
  • Silver tables are reusable by more than one Gold output.
  • Gold tables map to a named consumer: a report, a model or an API.
  • No layer exists only because the diagram has three boxes.

Planned articles on these topics

  • Medallion Architecture
  • Bronze
  • Silver
  • Gold
  • Data Architecture
  • Microsoft Fabric