Event-Driven Architecture

Overview

Patterns for async processing, background jobs, event publishing, and webhook handling. When synchronous request-response isn't enough.

Core principle: Use events for work that doesn't need to block the user's request. Keep the request path fast.

When to Use

• Sending emails/notifications after an action
• Processing uploads or heavy computation
• Syncing data between services
• Implementing webhooks (incoming and outgoing)
• Real-time updates (WebSocket, SSE)
• Any operation that takes > 500ms and doesn't need synchronous response

Pattern Decision