Strangler Fig

Three pillars; evolvability by style; strangler fig; six Rs; guidelines; antipatterns; DDD brownfield modernisation strategy; "form follows failure"; bad layering (horizontal coupling); component-based decomposition; decision loop speed and thrashing; service extinction; Farley: testability+deployability as operational drivers, TDD as architectural feedback, architectural descriptions as "tourist maps"

Decision tree: where's the seam, is correctness the dominant risk, granularity, duration, parallel-run cost; pattern composition (service extraction, embedded capability extraction, database split, platform migration); database decomposition patterns; rollback as a feature