Country codes, and other lookup tables, could easily be handled by a repository of config files. Or, if your company uses a single programming language, a libra

Country codes, and other lookup tables, could easily be handled by a repository of config files. Or, if your company uses a single programming language, a library. One strategy I've used is to designate one system as a source of truth (usually an ERP system) and periodically query its database directly to reload a cache. Every system works off their own periodically refreshed cache. Ideally, having all the apps query a read replica would prevent mistakes from taking down the source of truth. I haven't done this, but I think using Postgres with a combination of read-only foreign tables and materialized views could neatly solve this problem without writing any extra code. I don't know how far this would scale. I do know that coordination and procedures for using/changing the source of truth will fall apart long before technical limitations.