[karlmdavis]

You and I must work in very different contexts, as these questions are so obvious that they first seemed like satire to me.

You enforce API contracts in a monolith (or any codebase, really) via an at-least-modest amount of typing and a compiler. You diagnose performance issues via any number of tools, prominently including metrics and profilers.

My context for this is a lot of years working with backend languages like Java, Rust, etc. though the same assurances and tooling are available for most every platform I’m aware of.

[konschubert]

Sure… and then the type of the return object if of API is

‘CustomerORMModel’… and now the api consumer can build n+1 query problems across components.

You need a few more restrictions than that. But I agree it’s doable.