Technical Debt

Application-layer release control; Hodgson's four toggle types (release/experiment/ops/permission) with different lifecycles; flag lifecycle discipline; default behaviour and cohort routing; kill switches and load-shedding flags; flags as technical debt with a use-by date

Cohesion types, LCOM, coupling metrics, connascence taxonomy (static vs dynamic); SATH: applying D/A/I metrics to decomposition feasibility; Modularity Maturity Index (MMI 0-10, three cognitive principles: modularity 45%/hierarchy 30%/pattern consistency 25%, decision thresholds, architecture erosion, implementation vs design/architecture debt); advanced structural metrics: ACD/CCD/Propagation Cost, Relative Cyclicity, SDI, Maintainability Level, LCOM4, change history metrics, Component Rank, six golden rules

Ousterhout's complexity definition: three symptoms (change amplification, cognitive load, unknown unknowns), two causes (dependencies, obscurity), incremental accumulation; strategic vs. tactical programming; technical debt as borrowed time