Angular Signals are now the foundational reactive primitive for modern Angular, moving beyond experimental status. A new guide provides a scientific, production-minded analysis, comparing Signals directly with RxJS through empirical case studies. The focus is on evaluating their practical impact for large-scale applications, not just evangelizing their use.

Historically, Angular relied on Zone.js and RxJS for reactivity. RxJS was never designed as a UI state primitive, leading to mismatched complexity. Signals are synchronous, deterministic, and pull-based, making them ideal for state. A case study on idle user logout shows Signals reducing boilerplate and failure modes versus a BehaviorSubject approach.

For production, use Signals for component state and derived UI, while reserving RxJS for HTTP and streams. This separation is Angular's biggest architectural leap since Ivy. As Angular moves toward zoneless execution, mastering Signals becomes essential to avoid fighting the framework's new model.