I'm experimenting with something like that, to allow creating a web API from some descriptions in markdown.
https://github.com/lfarroco/verbo-lang
People say that a microservice is something that "fits in your head". Once the logic gets too complex, you should separate it into another service. Maybe in the future the phrase will be "what fits in the AI's context". That would be a good litmus test: if a piece of software is hard for an AI, maybe we should simplify it - because it is probably too hard for the average human as well.