From there we started looking for a narrative. We extracted out the sections you see in the final post, and removed a lot of the superfluous technical detail so we didn't end up with technology buzzword soup; for example we cut discussion of Postgres, Memcached, etc etc, how we host the web servers; the kind of details that don't actually matter to the narrative.
The illustrations were in the post from the beginning as Mermaid diagrams (https://mermaid-js.github.io/mermaid-live-editor/). As we got close to publication we polished them up in Figma.
This is really the first engineering blog post we've put out, there was a fair amount of figuring-out-how-to-do-it going on. Now that we've had the experience, we're starting to write up our playbook internally.