Sharpinterface

Sharpinterface is a concept in software engineering describing an approach to API and component interface design that prioritizes precision, minimalism, and well-defined contracts. The term is used to discuss how interfaces should present only what is necessary to interact with a component, reducing surface area and coupling while improving readability and maintainability. While not tied to a single formal standard, sharpinterface emphasizes clear responsibilities, stable behavior, and explicit failure modes.

Core characteristics include small, cohesive interfaces; explicit input and output types; well-named operations that map to a single responsibility; deterministic behavior; documented preconditions, postconditions, and error outcomes; strong typing; and versioning that preserves compatibility.

Practical applications include public APIs for libraries, service boundaries in microservices, plugin systems, and UI component APIs. Designers adopting sharpinterface typically apply principles such as the interface segregation principle, single responsibility, and defense in depth, preferring composition over inheritance and clear contracts over expansive surface areas.

Benefits include lower coupling, easier testing and mocking, greater clarity for consumers, simpler maintenance, and safer evolution of components. Trade-offs may involve more upfront design effort, slightly larger numbers of interfaces in some cases, and the risk of over-constraining flexibility if not balanced with practical needs.

See also: interface, API design, interface segregation principle, design by contract, type safety.