Rule Engine
A rule engine is a software system that executes business rules in a runtime production environment, separating business logic from application code to enable dynamic, declarative decision-making. It uses a set of rules (typically in an if-then format) to evaluate data and trigger actions, often supporting complex event processing and workflow automation. Rule engines are commonly used in areas like fraud detection, pricing calculations, compliance checks, and recommendation systems.
Developers should use a rule engine when they need to manage frequently changing business logic without redeploying code, as it allows non-technical stakeholders to modify rules through user interfaces. It is particularly valuable in domains requiring real-time decision-making based on multiple conditions, such as insurance underwriting, loan approvals, or e-commerce personalization, where rules can be updated independently of the core application.