interfacevary

Interfacevary, or interface variability, is a software design concept that describes intentionally varying the public interfaces of a component or service to meet diverse client needs while preserving core functionality. The approach exposes multiple interfaces or variant implementations so clients can interact with the component using the contract that fits their use case, without forcing all users to adopt a single API.

Origins and scope: Interfacevary arises in API evolution and modular architectures where stability is prized but client requirements differ. It is distinct from breaking changes: instead of removing features, variant interfaces are introduced alongside existing ones, with deprecation and migration paths to guide users toward preferred contracts.

Techniques and patterns: versioned interfaces (for example v1, v2), adapters and wrappers that translate between interfaces, functional options and builders, overloading or optional parameters, feature flags that switch behavior, and dependency injection to select implementations at runtime. Clear documentation and tests are essential to prevent fragmentation.

Examples: A data processing library might offer a simple synchronous interface for small jobs and an asynchronous streaming interface for large datasets. A cloud service could provide a minimal REST endpoint and a richer, parameterized GraphQL-like interface for advanced clients.

Trade-offs: Benefits include flexibility, smoother client migrations, and extended longevity of modules. Drawbacks include increased complexity, maintenance burden, and potential confusion among users. Good practice emphasizes stable core behavior, explicit depreciation timelines, and automated compatibility testing across all variants.

See also: API design, backward compatibility, semantic versioning, interface-based design, adapters, dependency injection.

References: See general resources on API evolution and interface design; no single standard governs interfacevary at present.