> ## Documentation Index
> Fetch the complete documentation index at: https://docs.siftstack.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Tutorial 7: Build reusable logic for consistent data transformation

> Centralize reusable transformation logic using User-Defined Functions

## Overview

By the end of this tutorial, you'll be able to create User-Defined Functions in Sift that encapsulate custom logic you can reuse across Calculated Channels and Rules. We'll walk through how to define these functions and apply them so you can keep your logic consistent, reduce duplication, and streamline your workflows.