Your payment just failed. The user needs to know before they try to check out again. Your deployment pipeline just finished. The engineer who kicked it off is waiting. A patient's appointment is in 24 hours and they haven't confirmed.
These are the moments where SMS works better than email. It's immediate, it doesn't get filtered, and it doesn't require the recipient to be looking at an app. Lambda is already where your event-driven logic lives. Connecting it to SMS is a few dozen lines of code.
This post uses the official Sinch SDKs. The examples cover Node.js and Python. Sinch also publishes SDKs for Java and .NET that follow the same pattern. If you'd rather manage the HTTP calls and OAuth token exchange yourself, there's a companion post that covers the raw HTTP approach using the same repo.
Prerequisites
The Sinch dashboard setup takes about 10 minutes. After that, sending is a single SDK call. You'll need a Sinch account (sign up here, a trial account is enough to test, see pricing for details), the AWS SAM CLI, and Node.js 22+ or Python 3.13+.
