PostgreSQL's foreign data wrappers (FDW) allow developers to expose external sources of data as tables inside PostgreSQL, enabling queries to be evaluated against both local and remote data sources. CARTO leverages FDW in two main ways: postgres_fdw for linking data between remote databases and users' Carto databases, and odbc_fdw for exposing operational database data to Carto instances. By utilizing the full-featured postgres_fdw implementation, CARTO achieves faster data access without replicating data from one database to another. To support spatial queries, CARTO extended postgres_fdw to include PostGIS geometry types and functions, enabling remote data access and generalizing their enhancements for use with any PostgreSQL extended type. Additionally, odbc_fdw enables schedule live data syncs between Carto instances and remote databases, supporting connections to various data sources such as MySQL, PostgreSQL, SQL Server, and Apache Hive.