Insights

dbt: Bringing Software Engineering to Data Transformation

How dbt makes SQL transformations modular, testable and documented, with a structure that scales.

dbt (data build tool) lets analysts and engineers write transformations as SELECT statements while dbt handles dependency ordering, materialization, testing and documentation. It turns a warehouse full of ad-hoc SQL into a maintainable codebase.

A project structure that scales

TEXT
models/
  staging/       -- one model per source table: rename, type-cast, filter
  intermediate/  -- reusable joins and business logic
  marts/
    finance/
    procurement/
    inventory/
    sales/

This maps directly onto the Medallion pattern: staging is silver, and marts are gold.

Tests are cheap insurance

YAML
models:
  - name: fct_purchases
    columns:
      - name: invoice_id
        tests: [unique, not_null]
      - name: supplier_key
        tests:
          - relationships:
              to: ref('dim_supplier')
              field: supplier_key

Run tests with every build so broken data is caught before it reaches a dashboard.

Use ref() and source() everywhere

They create the lineage graph, make environments switchable and let dbt build models in the right order.

Document for both audiences

Model and column descriptions in YAML generate a browsable documentation site. It is useful for technical teams and for business users who want to know what a metric means.

Fiaz Anjum

Senior Data Engineering & Business Intelligence Professional | Digital Transformation Specialist

About me · Discuss a project

  • dbt
  • SQL
  • Data Quality