Evolutionary Architecture

Architecture Decision Records: structure, anti-patterns, compliance governance, Type 1/2 decisions

Full classification taxonomy; priority tiers; enterprise fitness functions; mechanism and concern taxonomies; fitness function testing pyramid (triggered/continuous × atomic/holistic → three pyramid layers); ISO 25010 quality attribute anchoring

Independently deployable artifact; static/dynamic coupling distinction; quantum count by architecture style; micro-frontends (including EDM pairing); 3D dynamic coupling space → 8 saga types

*Building Evolutionary Architectures* — Ford, Parsons, Kua

Conway's Law; Inverse Conway Maneuver; three organisational structures (Pflaeging); tool choices as communication drivers; unexpected communication as diagnostic signal; organisation design as technical work

Fitness function automation; stages, fan-in/fan-out; CD vs CDP; cycle time as business metric; zero-downtime deployment (four phases: prepare/drain/apply/start); expand/contract relational schema pattern; trickle-then-batch schemaless migration; canary group evaluation; immutable infrastructure; EDM deployment patterns

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"

Expand/contract pattern; Flyway/Liquibase; shared DB decomposition; reporting antipattern; Newman's ~12 database decomposition patterns (database view, wrapping service, tracer write, synchronize in application, etc.)

DORA four key metrics (deployment frequency, lead time for changes, change failure rate, time to restore service); empirical basis (4-year, 23K+ respondents, Accelerate); Lean conceptual basis; cluster analysis; no-tradeoff finding; CABs negatively correlated with both metrics; Goodhart's Law warning; pipeline topology variants; instrumentation; MVD; virtuous cycle mechanism; complementary metrics

Domain-partitioned single quantum; appropriate coupling via fitness function enforcement; intermediate migration step

Author of *Fundamentals of Software Architecture* (with Richards), *Building Evolutionary Architectures*, *Software Architecture: The Hard Parts* (with Richards, Sadalage, Dehghani); contributing author *Software Architecture Metrics* ch. 8

*Software Architecture Metrics* — Ciceri et al.