When talking about data processing, people often abbreviate it as “ETL.” However, if we look closely, data processing has undergone several iterations from ETL, ELT, XX ETL (such as Reverse ETL, Zero-ETL) to the currently popular EtLT architecture. While the Hadoop era mainly relied on ELT (Extract, Load, Transform) methods, the rise of real-time data warehouses and data lakes has rendered ELT obsolete. EtLT has emerged as the standard architecture for real-time data loading into data lakes and real-time data warehouses.