AT3 — Simplicity/Flexibility: Start with the simplest architecture that satisfies current requirements. Every layer of abstraction added pre-emptively is complexity that must be maintained before it is needed. Add flexibility at the boundaries most likely to change.
AT12 — Tradeoffs as first-class outputs: The deliverable of system design is not an architecture diagram but a set of documented tradeoff decisions. An architecture without documented decisions cannot be maintained because the team cannot know what will break when they change something.
AT5 — Centralisation/Distribution: Every component that exists as a single instance is a SPOF (FM1). Identify which centralised components are acceptable risks and which require distribution before the design is complete.