It also seems like part of your pain point is that there is an any-to-any relationship between proxy and backend, but that doesn’t need to be the case necessarily, cell based architecture with shuffle sharding of backends between cells can help alleviate that fundamental pain. Part of the advantage of this is that config and code changes can then be rolled out cell by cell which is much safer as if your code/configs cause a fault in a cell it will only affect a subset of infrastructure. And if you did shuffle sharding correctly, it should have a negligible affect when a single cell goes down.
