The other day I asked for an analysis or at least an UML diagram since we are having quite some troubles and my boss looked disgusted at me for asking such a question. I’m not a professional backend developer, so I don’t know how it works professionally
I’ve found most places aren’t very good at explaining the system design. Just make one yourself from what you understand, that’ll help you figure out how the system works, and your team will usually correct anything you got wrong (assuming it’s small enough to quickly review and notice incorrect assumptions).