One of the most frequent questions I receive from DP-600 learners and data professionals is:

“How do we properly ingest and transform data in Microsoft Fabric?”

The Confusion Ends Here

Working with Microsoft Fabric? Then it's only a matter of time before encountering the acronym "UDF"—and wondering what it really means. Is it a Power BI thing? Data Engineering? The answer is: it's both.

The good news: once the distinction is clear, choosing the right UDF becomes intuitive. And more importantly, understanding both reveals how Fabric's workloads are designed to work together seamlessly.

What Makes UDFs Worth Understanding

Both User Defined Functions (in Power BI) and User Data Functions (in Data Engineering) embody the same software engineering principle: modularity and the DRY principle—Don't Repeat Yourself. Yet they solve completely different problems.

Power BI's UDFs let analysts encode business logic once and reuse it across every dashboard and report. Data Engineering's UDFs enable data engineers to write transformations once and apply them wherever data needs to be processed. In both cases, the benefit is the same: one source of truth, no duplicated code, and centralized maintenance.

It's the difference between building consistent analytical metrics and processing data at scale—and why organizations need both.

Dive Deeper

Curious about how to leverage both? Ready to architect Fabric solutions that follow software engineering best practices?

Microsoft Fabric revolutionizes data architecture by offering a unified platform that integrates Power BI, data science, real-time analytics, and more. At the heart of this ecosystem is the Lakehouse, a powerful, flexible, and scalable storage layer tailored for modern data engineering workflows.

In this article, we explore how Lakehouses work in Microsoft Fabric, how to set one up, and how they serve as the foundation for managing both files and structured data—all without the traditional complexity of data platforms.

OneLake is a unified storage system in Microsoft Fabric that eliminates data silos by storing all data in a single location. Now, we’re going to discuss Direct Lake, a new way Power BI interacts with this storage for faster performance and efficiency.

Source: https://learn.microsoft.com/en-us/fabric/fundamentals/direct-lake-overview