Declarationsbased

Declarationsbased is a design and development approach that emphasizes constructing software systems primarily around declarations—statements that specify desired properties, constraints, or outcomes—rather than explicit procedural steps. In a declarationsbased paradigm, the system's behavior is derived by a declarative engine (such as a constraint solver, rule engine, or data validator) that ensures the declared conditions hold, leaving the how to implementers or the engine.

Key ideas include separating what is intended from how it is achieved. Interfaces specify declarations; implementations provide the mechanisms that satisfy them. The approach is often used with domain-specific languages or configuration languages and is compatible with model-driven engineering and data-centric architectures.

Common features encompass declarative syntax, automatic inference or validation, and a strong emphasis on data models and invariants, which can improve portability across environments and ease reasoning about system state. Limitations include potential performance costs, a learning curve for teams, and gaps between high-level declarations and low-level effects.

Applications span configuration management and infrastructure as code, data validation schemas, policy and compliance rules, business process modeling, and AI rule systems. Examples include declarative configurations, schema definitions, and rule-based pipelines.

History notes that the term appears in limited technical discussions and some industry blogs to describe a design stance rather than a formal standard. It is typically discussed in relation to broader declarative programming and model-driven approaches rather than as an independent paradigm.

See also: Declarative programming, constraint programming, rule engines, model-driven engineering, configuration as code.