Serious question:

If you take a BDD/TDD approach - do technologies like this still give you something?

I've dabbled a bit into smth similar (SpacetimeDB) with the aim of creating a headless backend for a game.

But then I realized that I'd still need to define the interface that I was testing in the traditional software layer and that all the nice DB magic seemed worthless since I'd still have to orchestrate traditionally.

(In short: No matter how nice your DB magic is, you will still hide it away in the basement/engine room, right?)