Which goes nicely with Day 6 and 7 of the Adventure in System Seeing:
https://www.ruthmalan.com/Advent/2025/Day6.html

Everything is connected to everything (eventually) :)

That post by @stephenpa also points to a Causal Loop Diagram exploring TikTok’s networks of causal influences and ripple effects

https://www.linkedin.com/posts/sreesevithaa_system-wisdom-series-ugcPost-7402080857005441024-WpFZ

In “Facilitating Software Architecture,” @ahl draws on Booch and Fowler:

“What is software architecture? For Grady Booch, "[Software] architecture represents the set of significant design decisions that shape the form and the function of a sys-tem, where significant is measured by cost of change." Martin Fowler has a similar take that can be paraphrased as software architecture being those decisions that are both important and hard to change?”

Of course, I take pages to raise the question (with obligatory humor about “it depends”), then offer one of the characterizations that captures a helpful essence that is worth exploring:

"Architecture represents the significant design decisions that shape a system, where significant is measured by cost of change."
- Grady Booch

This Overview explores software architecture as (not all of, but importantly) system design:
https://www.ruthmalan.com/systems/2025SystemDesignOverview.pdf