https://c4model.com/ https://c4model.com/ is very useful for this. :-) I've told it before, but when we were doing some clean sheet work a while ago I decided

https://c4model.com/ https://c4model.com/ is very useful for this. :-) I've told it before, but when we were doing some clean sheet work a while ago I decided to use the C4 model and drew out the obligatory "Context" diagram with "user" "phone" "laptop" "app" sort of stuff. I found them silly and (honestly) I still find that if I see one "in the wild" with no further elaboration I become suspect. However two hours later, because of that silly context diagram, I realized that we had both an online and a semi-disconnected mobile app that could be offline for hours, and that certain things -had- to use a queue and expect an arbitrary amount of time for a task to run, and it completely changed how we thought about the core of how we implemented something pretty important. Sold. :-)