Architecture Design

Once the bounded contexts were identified, we designed the Nucleo architecture around a microservices approach to keep components cohesive and independently evolvable.

The current architecture includes the following services:

• frontend-service: serves the web application.
• users-service: users, authentication, authorization, delegations, and notifications capability.
• documents-service: prescriptions, reports, uploads, and document metadata.
• appointments-service: availabilities and appointment lifecycle.
• master-data-service: facilities, medicines, and service types.
• ai-service: document analysis support and AI-assisted extraction.

In addition to business services, the platform relies on infrastructure components:

• API Gateway (Nginx) for north-south traffic routing.
• Kafka as event broker for asynchronous integration.
• Dedicated data stores owned by each service.

Component & Connector View

This view describes the runtime components and their interaction styles.

Interactions

Nucleo uses two main communication patterns:

• External communication: clients call the frontend, which reaches backend APIs through the gateway.
• Internal communication: services collaborate with synchronous HTTP calls when immediate consistency is required, and with Kafka events for process decoupling and eventual consistency.

Proposed Architecture

Architectural Rationale

• Bounded contexts map to service boundaries to preserve domain clarity.
• Database-per-service enforces ownership and reduces accidental coupling.
• Event-driven collaboration through Kafka improves autonomy and resilience.
• Gateway-based ingress keeps external APIs controlled and evolvable.