structural

To decouple incompatible interfaces in software design, apply the Adapter pattern to translate one interface into another that a client expects, enabling collaboration between incompatible types without modifying existing subsystems.

The best way to integrate legacy code without subclass explosion is using structural patterns like Decorator or Bridge to compose behaviors dynamically, preserving existing functionality while adding new responsibilities through object composition rather than inheritance.

Use the Facade pattern to manage complex subsystems when you need to provide a unified interface to a set of interfaces, reducing coupling and simplifying client interactions by hiding internal complexity behind a single entry point.

Yes, structural design patterns reduce subclass proliferation by favoring object composition over inheritance, using patterns like Decorator and Composite to dynamically add responsibilities or build tree structures without deep class hierarchies.

Choose Bridge when you need to separate an abstraction from its implementation so they can vary independently, and select Adapter when you must make an existing incompatible interface work with a target interface without changing either subsystem.