SharePoint - Asynchronous Events

The following is a SharePoint Dictionary word of the day:

Asynchronous Events in SharePoint: Why They Matter and How They Work

If you work with SharePoint development or customization, you’ve probably heard the term asynchronous event. It sounds technical, but understanding it can dramatically improve how you design event receivers, workflows, and custom logic across your SharePoint environment.

What Is an Asynchronous Event?

An asynchronous event is an event whose handler runs in a separate processing thread from the action that triggered it. In other words, SharePoint doesn’t wait for the event handler to finish before continuing its normal operations.

This means the event action (such as adding an item) and the event handler (your custom code) run simultaneously, without blocking each other.

Why SharePoint Uses Asynchronous Events

Asynchronous events are essential in scenarios where you want SharePoint to stay fast and responsive. They’re ideal when your custom logic takes time - such as calling APIs, updating multiple lists, or performing heavy calculations.

Here’s why they’re powerful:

1. Non-blocking performance — SharePoint continues processing without waiting for your code.
2. Better user experience — Users don’t feel delays when saving or updating items.
3. Scalability — Long-running operations don’t slow down the entire farm.
4. Parallel processing — SharePoint and your handler run at the same time.

Real-World SharePoint Example

Imagine a user uploads a document to a library. You want to:

• Extract metadata
• Send a Teams notification
• Update a dashboard list
• Trigger a Power Automate flow

Doing all of this synchronously would slow down the upload.

With an asynchronous event, SharePoint saves the file instantly while your custom logic runs in the background.

When to Use Asynchronous Events in SharePoint

Use them when your logic is:

• Time-consuming
• External-system dependent
• Non-critical to the immediate user action
• Batch-oriented

Avoid them when you need immediate validation or must block the action.