Not sure this holds water. Which SOLID principle, or combination, solves the problem of building a system where a request traverses a boundary that is not prob

Not sure this holds water. Which SOLID principle, or combination, solves the problem of building a system where a request traverses a boundary that is not problematic when executed locally, but introduces too much latency when you put a new network call behind an interface? From what I can see, SOLID lets you split the monolith, as long as you happen to have interface segregation on the right seams. It says nothing about the operational properties of the service once split, which is by far the bigger problem, and depends on the non-functional properties of the code using the interfaces. Unless you already know you are headed for a microservice split, you're unlikely to have designed with that in mind.