Press enter or click to view image in full size
Apple: confidence through exhaustive validation. Rego favors flexibility. It can express complex rules, traverse nested data, and support policy decisions across many resource types. That power makes broad formal analysis difficult, so assurance comes from engineering discipline: unit tests, negative tests, regression suites, policy review, and production telemetry. The governing idea is practical rather than mathematical: define the expected behavior, test the edge cases aggressively, and prove reliability through repeated execution.
Google: policy as a compact embedded expression. CEL is designed to be small, fast, and easy to embed inside existing systems. It works well for validation rules, admission checks, conditional logic, and request-time constraints. Its value comes from limiting the problem. CEL does not try to become a complete authorization platform. It provides a concise expression layer that application and infrastructure teams can integrate without deploying a separate policy runtime or learning a large policy framework.
Amazon: assurance through analyzability. Cedar deliberately restricts what policy authors can express so the resulting policy set remains predictable and open to formal reasoning. Its type system, entity model, and constrained syntax support questions that testing alone cannot fully answer: whether one policy shadows another, whether a class of requests can ever be permitted, or whether a security invariant always holds. The tradeoff is less general-purpose flexibility. The benefit is stronger evidence that the entire policy system behaves as intended.