Defense programs succeed when they can absorb new technology without rewriting the playbook. Threats, sensors, processors, and waveforms all move at different speeds, and programs that hinge on bespoke integration struggle to keep up. The alternative is to treat the system as a set of well-bounded parts whose interfaces are more important than their internals. With that mindset, teams can refresh capability on a predictable cadence instead of waiting for once-in-a-decade overhauls.