Building Scalable Salesforce Integrations with Platform Events

In today’s API-driven landscape, real-time integration is key. Salesforce Platform Events provide a powerful event-driven architecture that helps developers build scalable, loosely-coupled integrations across systems.

In this comprehensive guide, you’ll learn how to use Platform Events to build responsive, scalable, and maintainable integrations inside and outside of Salesforce.

What Are Platform Events?

Platform Events are part of Salesforce’s Event-Driven Architecture (EDA), allowing systems to communicate through publish-subscribe models. Instead of querying for changes or writing synchronous APIs, you publish and subscribe to events asynchronously.

Key Benefits:

• Real-time communication between systems
• Decoupling of apps and logic
• Improved scalability via asynchronous processing
• Transaction boundary control

Platform Events vs Traditional Integration

When to Use Platform Events

• Notify external systems when data changes
• Integrate with middleware like MuleSoft, AWS, or Kafka
• Trigger downstream actions from Apex or Flows
• Replace Outbound Messaging with more reliability

Creating a Platform Event

1. Go to Setup → Platform Events
2. Click New Platform Event
3. Define the name (e.g., Order_Event__e)
4. Add custom fields like OrderId__c, Status__c, or CustomerEmail__c
5. Click Save

Platform Events use the __e suffix and behave like sObjects.

Publishing Events from Apex

Publishing a Platform Event is as simple as inserting a record:

Order_Event__e event = new Order_Event__e(
    OrderId__c = '12345',
    Status__c = 'Shipped',
    CustomerEmail__c = 'user@example.com'
);
Database.SaveResult sr = EventBus.publish(event);

You can publish from Apex triggers, classes, or even Flow Builder.

Subscribing to Platform Events

1. Apex Trigger on Platform Events

trigger OrderEventTrigger on Order_Event__e (after insert) {
    for (Order_Event__e evt : Trigger.new) {
        System.debug('Received Order ID: ' + evt.OrderId__c);
        // Execute business logic
    }
}

2. Process Builder or Flow

You can create declarative subscribers in Flow Builder that listen to Platform Events and execute logic like record creation or email alerts.

3. External Subscribers

External systems (e.g., AWS Lambda, Node.js apps) can subscribe via CometD using Salesforce’s Streaming API.

Real-World Use Case: Ecommerce Order Processing

1. Salesforce publishes an event when an order is marked “Shipped”.
2. AWS Lambda listens and updates shipping labels via an external API.
3. Slack Bot posts an order shipment update.
4. Salesforce triggers follow-up task creation via Flow.

This architecture is fully asynchronous, event-driven, and scalable.

Best Practices for Platform Events

1. Monitor Replay IDs

Use replay IDs for durable subscriptions and guaranteed delivery in case of disconnections.

2. Limit Event Volume

Platform Events are subject to limits (e.g., 150K events/day for Enterprise Edition). Monitor usage via Event Monitoring.

3. Batch Processing

Use Apex triggers with future or queueable classes for processing to avoid long-running operations.

4. Use EventBus.publish()

Use EventBus.publish() to publish events instead of DML for enhanced control and error handling.

5. Test with Test.startTest() and Test.stopTest()

Use Test.getEventBus().deliver() in unit tests for reliable testing of event-based logic.

Platform Events vs Change Data Capture (CDC)

Use CDC for tracking changes and Platform Events for broadcasting messages across apps.

Monitoring & Debugging

Tools:

• Event Monitoring Logs: Track published/subscribed events
• CometD Clients: Use Postman or JavaScript clients to test subscriptions
• Debug Logs: Capture Apex trigger logs on events
• Transaction Finalizer: Ensure retry logic for external system sync

Scaling Tips for Large Orgs

• Batch-trigger processing with Queueable Apex
• Create custom retry logic for failed subscribers
• Split event schemas by function (e.g., Shipping_Event__e, Inventory_Event__e)
• Use platform cache or custom metadata to throttle volumes

Conclusion

Platform Events are a cornerstone for modern, scalable Salesforce integrations. They provide the speed, flexibility, and decoupling needed to build reliable cross-system architectures.

Start using Platform Events today to unlock true real-time automation in Salesforce.

Need help architecting your integration? Drop your scenario in the comments, and let’s discuss the best event-driven design!