Ensuring Data Quality in Cross-Border Survey Analysis

PayPal has teamed up with a regional survey platform to perform market research for their Southern African operations. Due to strict regulations in the area, all survey data must be stored within each country's borders in the platform's data centers. While much of the survey data is pre-quantified, a significant portion consists of raw text data in various regional languages. To consolidate analytics efforts, a translation module is employed to facilitate a unified analysis of the region. As a consulting engineer, your task is to evaluate the ETL pipeline that links PayPal's data marts to the survey platform's data warehouses. This includes an additional ETL layer that connects transactional data stores to the survey platform's data warehouse and normalizes this data through translation modules. What steps would you take to ensure data quality across these diverse ETL platforms?