1. Strategy Patternhistorical

    Encapsulating interchangeable algorithms or policies behind a common contract.

  2. Observer Patternhistorical

    Notifying registered observers about subject changes and managing coupling, ordering, and lifecycle.

  3. Decorator Patternhistorical

    Adding composable behavior around an object without changing the wrapped implementation.

  4. Chain of Responsibilityhistorical

    Passing a request through an ordered pipeline of handlers that may process, enrich, reject, or forward it.

  5. Adapter Patternhistorical

    Translating one interface/protocol/data model into the contract expected by a client.