The concept of ETL, Extract, Transform, Load, has been a traditional method for managing analytics pipelines for decades but is changing with the advent of modern cloud-based data warehouses such as BigQuery or Redshift, which are shifting towards ELT - when transformations are run directly in the data warehouse. The traditional ETL process is complicated and outdated, requiring significant time and resources to implement and maintain, particularly during transformation rules changes. Modern data warehouses have optimized for analytical operations, offer cheap storage, and are cloud-based, making it possible to perform transformations in the background or at query time, providing flexibility and agility for development of a transformation layer.