Executive Summary: Breaking down monoliths using RabbitMQ, Redis Pub/Sub, and Event Sourcing.

As Solidrix Send grew, processing everything in a single Laravel monolith became difficult. We transitioned to an event-driven architecture. ### The Publisher-Subscriber Model Instead of tight coupling, components emit events. When a user registers, the Auth service fires a `UserRegistered` event to a message broker (RabbitMQ/Redis). - The Email Service listens and sends a welcome email. - The Analytics Service listens and updates marketing stats. - The Billing Service listens and creates a Stripe customer. This architecture ensures that if the Email Service crashes, the registration flow doesn't break. The event simply waits in the queue until the service is restored.