Laravel Event Projector Laravel Package

Product Decisions This Supports

• Event-Driven Architecture (EDA) Adoption: Enables teams to transition from traditional CRUD to event-driven workflows, improving scalability and auditability. Aligns with roadmaps for microservices or real-time systems.
• Build vs. Buy: Avoids reinventing event sourcing infrastructure, reducing dev time and technical debt. Ideal for teams already using Laravel.
• Use Cases:
  • Audit Trails: Track changes to critical data (e.g., financial transactions, user actions).
  • Real-Time Updates: Power live dashboards or notifications via projected state changes.
  • Data Reconciliation: Rebuild aggregates from historical events for consistency (e.g., after migrations or corruption).
  • Decoupled Services: Enable asynchronous processing between services via events.
• Tech Stack Alignment: Leverages Laravel’s ecosystem (e.g., queues, Eloquent) for seamless integration with existing projects.
• Future-Proofing: Migrates easily to spatie/laravel-event-sourcing (successor package), ensuring long-term viability.

When to Consider This Package

• Adopt When:

  • Your team needs immutable audit logs or temporal queries (e.g., "Show me all user actions from last week").
  • You’re building scalable, stateful systems where traditional ORM patterns (e.g., direct DB updates) are limiting.
  • You require decoupled event processing (e.g., reactors for side effects like analytics or notifications).
  • Your Laravel project already uses queues or Eloquent, reducing integration friction.
  • You prioritize developer velocity over custom event-sourcing implementations.

• Look Elsewhere If:

  • You need active maintenance: This package is archived; migrate to spatie/laravel-event-sourcing (v1+).
  • Your use case demands high-throughput event streaming (e.g., Kafka/SQS-native solutions like Laravel Serenity).
  • You’re not using Laravel: Consider framework-agnostic tools like EventStoreDB or Axon Framework.
  • Your team lacks event-sourcing maturity: Start with simpler patterns (e.g., Laravel Observers) before adopting event sourcing.
  • You need multi-model projections (e.g., GraphQL + event sourcing); this package focuses on SQL projections.

How to Pitch It (Stakeholders)

For Executives/Business Leaders

"This package lets us build systems where every change is recorded as an immutable event—like a blockchain for our business logic. For example, in [Use Case X], we can instantly reconstruct any past state of a critical record (e.g., a financial transaction) or trigger real-time updates to dashboards without manual syncs. It’s like adding a time machine to our data, reducing errors and enabling features like ‘undo’ or ‘roll back’ for high-stakes actions. The trade-off? A modest upfront investment in rethinking how we model data, but long-term gains in reliability and scalability. Oh, and it’s built for Laravel, so our existing team can adopt it quickly."

Key Outcomes:

• Regulatory Compliance: Unchangeable audit trails for industries like finance/healthcare.
• Operational Efficiency: Debugging and recovery become trivial (e.g., "What happened to Order #12345?").
• Feature Velocity: Build real-time features (e.g., live collaboration tools) without custom infrastructure.

For Engineering/Technical Stakeholders

*"This is a battle-tested way to implement event sourcing in Laravel with minimal boilerplate. Here’s why it’s a no-brainer:

• Aggregates: Model domain entities as event streams (e.g., UserAggregate emits UserRegistered, EmailVerified events).
• Projectors: Materialize read-optimized views (e.g., UserProfile table) from events via SQL queries.
• Reactors: Handle side effects (e.g., send welcome email when UserRegistered fires) with decoupled logic.
• Laravel Native: Integrates with queues, Eloquent, and migrations—no foreign frameworks needed.

Migration Path: The package is archived but trivial to upgrade to spatie/laravel-event-sourcing. We’d start with a spike to validate:

1. Performance (event replay speed for large datasets).
2. Team onboarding (complexity of defining aggregates/projectors).
3. Tooling gaps (e.g., testing event streams, handling schema migrations).

Alternatives: If we need more than SQL projections or active maintenance, we’d evaluate Laravel Serenity or build a custom solution—but this gives us 80% of the value with 20% of the effort."*

Tech Deep Dive:

• Example Workflow:

  // Define an aggregate
  class UserAggregate {
      public function register(string $email) {
          $this->recordThat(new UserRegistered($email));
      }
  }
  
  // Project to a read model
  class UserProfileProjector {
      public function onUserRegistered(UserRegistered $event) {
          UserProfile::create([...]);
      }
  }
  

• Trade-offs:
  • Complexity: Event sourcing requires discipline (e.g., handling event versioning, replaying streams).
  • Storage: Events accumulate over time (plan for DB growth).
  • Testing: Shift from unit tests to event replay tests.

Call to Action:

• "Let’s prototype this for [High-Impact Use Case] in 2 weeks. If it delivers the auditability/real-time benefits we need, we’ll prioritize migrating to the successor package."