Your First Task as a Data Engineer in a New Company? Make the ETL Pipeline Testable

When joining a new company, a data engineer should prioritize making inherited ETL pipelines testable to address common issues like schema changes and poor data quality. An automated testing workflow provides a structured way to understand business logic and data transformations. The setup involves creating an isolated, reproducible environment using Docker, VS Code, and the Dev Containers extension. The article explains how to use unit tests for specific functions and integration tests to validate the entire pipeline, providing a PySpark example for an AI cost tracking system.