I am not sure if W3C EXI, or ASN.1 BER or something else is better, but agree that using DOP (rather than OOP) design principles is the right answer -- which means focusing on the encoding first, and working backwards towards the languages / clients.
DOP is great, but there’s always a gap between DOP and OOP. That gap is where Fory comes in. Right now, Fory takes an OOP‑first approach, but next we’ll add a DOP path by introducing an optional IDL — bridging the two styles. My goal is for the IDL to also support optional OOP‑style expressiveness, so teams can choose the balance that fits their needs.
DOP is very interesting, I like this idea too — most DOP approaches are implemented via an IDL, which is another valid direction. I plan to support that in Fory. I want to give users the freedom to choose the model that works best for them.