ETL Migration and Legacy Technology Decommissioning Case Study

This case study outlines the project focused on the migration of ETL processes and the decommissioning of outdated technology at Česká spořitelna, a major Czech bank. The objective was to transition a significant portion of the business intelligence landscape into a modern framework, successfully phasing out operations on legacy systems. The project involved the migration of 130 complex ETL processes, including 1,200 individual data mappings, which resulted in a substantial reduction of ETL runtime by multiple machine days through SQL performance tuning initiatives. The client aimed to optimize licensing structures, address performance concerns, enhance ETL development capabilities, and consolidate IT tools and systems. The project faced challenges in maximizing automation for regression testing and ensuring the migrated processes functioned correctly. The successful completion of the migration, which took place from October 2022 to December 2023, led to significant improvements in the efficiency and reliability of the data warehouse and analytical platform.