So, if I understand it correctly, Middleware and Backend should have been single component since it's one bounded context and splitting it makes one of those feature envy? Is there some benefit keeping these separate or is the cost of change too high at this point?
If it's not about features, but more about API, have you tried Consumer-driven contract testing approach?
The reason was, you can have more instances of backend for a single middleware and that should have helped with scalability.
If we had the resources to do the refactoring, we would probably end up with two-three different backends for various contexts, and without the middle-man between the gui and the backends.
On the other hand, the cost of change is probably too high, and most probably this version of our product will be kept on minimum-resource life support.
We are looking for doing consumer-driven testing for our new set of services we are working on.
