Their elixir app masquerades as a postgresql database so that existing tools that can connect to pg can connect to the AirCloak instead - that's pretty wild.
"By understanding the server-side of the PostgreSQL protocol, the Air can accept connections from PostgreSQL aware tools, such as psql. This trick allows us to integrate with analytical tools, such as Tableau"
This seems to be usable as a database only for analytics purposes because of privacy-preserving features such as "low-count filter: any response is silently suppressed if fewer than some small number of distinct users have that value."