Legacy ETL migrations present a significant opportunity and challenge for partners assisting enterprises in transitioning to modern data platforms like Snowflake, Databricks, Redshift, or BigQuery. These migrations can be a billion-dollar opportunity, but getting them wrong can lead to friction and undermine trust in modernization efforts. Many enterprises face hurdles due to decades-old ETL pipelines that are crucial for executive dashboards, regulatory reports, and workflows. These projects are often avoided because they are perceived as risky, expensive, and difficult to estimate, yet they hold the potential to accelerate modernization when unlocked. Successful migration requires partners to bring the right tools and technology to the table, as confidence in handling these complex and embedded data systems is paramount. Historically, ETL pipelines were created using desktop GUIs, running in memory with logic stored in config panels and proprietary systems, lacking modern practices such as version control and automated testing, yet they continue to support essential operations in major enterprises.