I like C4. I'd previously discounted the "context" diagrams that inevitably show "User -{do their job}-> System-of-Record" as useless. Now I see the point. I'm

I like C4. I'd previously discounted the "context" diagrams that inevitably show "User -{do their job}-> System-of-Record" as useless. Now I see the point. I'm working through a new piece of system design for a complex system using C4 with our extended teams. In drawing the top level this time around though I realized that b/c we have a semi-disconnected mobile app (aside from a web UI) we need to degrade certain behaviors gracefully if we don't have certain results yet, either b/c we're offline, or the backend is just slow for some reason. That rippled down into the next layer of the system as a job queue, which then rippled into the UX, because we can now say definitively which parts of the system may take an unbounded amount of time to complete a request. I'm sure we'd have gotten to this conclusion eventually but the analysis put the issue front and center. All because I had to draw a picture with "Remote-User --{Mobile Stuff}--> Backend." Also whichever tool you use is up to you. I just use draw.io for example with different tabs for each layer. As we elaborate on this at some point we'll break the lower layers out to their own files.