Structural Pattern Selector

When to Use

You have a structural design problem — one about how classes or objects are composed to form larger structures. This skill applies when:

• Two classes need to work together but have incompatible interfaces
• An abstraction and its implementation are tightly bound and you need them to vary independently
• You need to build tree-like hierarchies where individual items and groups behave the same way
• You need to add capabilities to objects at runtime without subclassing
• A complex subsystem needs a simpler unified entry point
• You're creating large numbers of similar lightweight objects and memory is a concern
• You need a stand-in, gateway, or access-control layer in front of another object
• You're unsure which structural pattern fits, especially between Adapter/Bridge or Composite/Decorator/Proxy

Not this skill if: The problem is about object creation (use a creational pattern) or communication/algorithms between objects (use a behavioral pattern). If you haven't yet classified the problem as structural, invoke design-pattern-selector first.

Context & Input Gathering