Design Patterns

Design Patterns are reusable, named solutions to problems that recur across software design. Rather than dictating finished code, a pattern describes the shape of a solution — the participants, their relationships, and the trade-offs — so teams can apply a proven approach to their own context. The idea was popularized by the 1994 Gang of Four book, which catalogued patterns like Factory, Observer, and Strategy that remain part of a working engineer’s vocabulary.

• Creational patterns - Factory, Builder, and Singleton govern how objects are constructed and shared.
• Structural patterns - Adapter, Facade, and Decorator compose objects into larger structures without rigid coupling.
• Behavioral patterns - Observer, Strategy, and Command organize how objects communicate and delegate responsibility.
• A shared vocabulary - Naming a pattern lets a team discuss architecture at a higher level of abstraction, which is the pattern’s real payoff.

In the API space, the same instinct shows up as design patterns for resources, pagination, error formats, and base URLs — conventions that make one API feel like the next and lower the cost of integration. I have spent years documenting the common patterns providers converge on across hundreds of APIs, because consistent patterns are what make a catalog legible to humans and, increasingly, to agents. They sit alongside formal Design Standards and practices like Dependency Injection in a mature engineering culture.