When is Async Programming Useful?

There are three main benefits to using async programming:

Improved throughput #

Because your application doesn’t have to block on one operation before making progress on other work, it can often handle more work over the same period of time. This is particularly valuable in applications such as web servers that may be handling many requests concurrently.

Better resource utilization #

Waiting for I/O doesn’t necessarily require a thread to sit blocked until the operation completes. With asynchronous I/O, execution resources can potentially be used for other work while the application waits for the database, network, filesystem or another external resource.

Better responsiveness #

Async programming can also help applications remain responsive while longer-running operations are taking place. In a user interface, for example, you generally don’t want the entire application to freeze while it waits for a network request or file operation to complete.