Orchestrating Scalable Frontends: The Power of the Composition Root

In previous chapters, we built the foundations of our frontend architecture. With Atomic Design, we organized our UI into shared/components, separating reusable, domain-agnostic elements from specific contexts. With Feature-Driven Architecture, we isolated the domain by introducing features/ as autonomous business units. But a real-world application isn't just a collection of isolated modules. It is a system where domains must collaborate. The question becomes inevitable: How can we allow features to communicate with each other without destroying the isolation we just built? The answer lies in introducing a higher level of orchestration: the Pages layer acting as a Composition Root. Revisiting the Structure Our architecture, consistent with our previous principles, looks like this: src/ ├─ shared/ # Reusable UI & utilities (Atomic Design) ├─ features/ # Isolated domains (Feature-Driven) │ ├─ cart/ │ └─ checkout/ ├─ pages/ # Orchestration & Composition Layer └─ app/ # Global bootstrappi