The start of a practical series on migrating old SQL code into modularized, business-friendly data transformations.
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Why Legacy SQL Migration Matters
If you’ve worked in data engineering for more than a few years, you know the reality: enterprises are full of legacy SQL. Complex, deeply nested queries built over decades. Business logic buried inside layers of joins, unions, and transformations.
The problem? These queries are:
Opaque: nobody really understands what they do anymore.
Brittle: a single schema change can break entire workflows.
Hard to test: no modularization, no clear lineage.
To move toward model-driven data engineering and business-friendly mapping, we need to bring these queries into a controlled, structured framework.
That’s what this series is about.
The Migration Journey
This series will walk through a step-by-step migration pipeline:
