What if we treated Postgres like SQLite?

The PostgreSQL data directory format is not very stable or portable. You can't just ZIP it up and move it to a different machine, unless the new machine has the same architecture and "sufficiently" similar PostgreSQL binaries.

In theory the data directory works with any PostgreSQL binaries from the same major version of PostgreSQL, but I have seen cases where this fails e.g. because the binaries were from the same major version but compiled with different build options.

Yeah, that really is a great thing about SQLite.

I wonder whether packaging everything in Docker (including a specific Postgres container identified by hash or whatever) and deploying on the same architecture would solve this?