Most of the discussions about approaches are about shifting the locus of "common language" at a particular point between the producer and the consumer. The comm

Most of the discussions about approaches are about shifting the locus of "common language" at a particular point between the producer and the consumer. The common language is basically a codified description of the data that is highly (ideally always) predictable, so that the producer and consumer both speak that language at all times at the boundary of information exchange between the 2 systems. Something like RPC nudges towards the producer (or backend); graphql moves it to the consumer (or frontend). A different way is to not look at this as a line of information flow between 2 points, by introducing a 3rd party, an impartial standards body. Maybe it's just a semantic or procedural difference, but when the locus is defined at the meta-architecture level there's no more room for discussion about exactly where you place the locus. Pay the vendor before you ship, or pay the courier when you receive? Neither: introduce an escrow.