I recently came across the C4 model, I believe from a Hacker News comment responding to a request for architecture diagramming methods when I was performing a web search for the same. The talk I watched was another one, but I pretty quickly became sold on it. I am trying to implement it for a system that I am new to.

Really, the main struggle is tooling. So far, I am using PlantUML with a C4 model plugin. It's okay. I am thinking of switching to a visual diagramming tool, even though the author of the C4 model recommends against it, for some reason that I don't quite understand.

It seems this talk, which I'll have to watch later, is own the author's own tooling called Structurizr. While nice, the pricing is a bit strange. The on premise version is $50 minimum per month and is twice the cloud version. I feel like it's going to be hard enough selling the C4 model, and I don't think the pricing model works for something that will have a lot of work in the beginning and then become relatively static for mature products. I'd like to see a one-time purchase perpetual license.