(document) “architecturally significant” decisions: those that affect the structure, non-functional characteristics, dependencies, interfaces, or construction techniques.

Quoted from Michael Nygard

Don’t document every tiny development decision - but concentrate on the following:

  • critical or important for the system
  • influencing important quality attributes
  • unconventional (“off the beaten track”)
  • risky
  • with expensive consequences
  • with long-lasting effects
  • affecting either
    • a large number of stakeholders
    • very special or important stakeholders
  • that took a long time or much effort to decide
  • astonishing