Can you use custom errors with asynchronous functions (e.g., Promises)?

Yes, you can absolutely use custom errors with asynchronous functions and Promises. When an error is thrown within a Promise's `then` or `catch` block, it propagates through the Promise chain. You can throw your custom error within the Promise and handle it in a subsequent `catch` block, just like with synchronous code. Ensure your `catch` block uses `instanceof` to correctly identify and handle the custom error.