The article describes a tutorial on how to build a serverless gym app that sends a workout plan to a WhatsApp number using ChatGPT, AWS Lambda, and Twilio.

The tutorial covers building a Lambda function in Go, integrating with OpenAI, setting up a Twilio account, deploying the app with AWS SAM, setting up a trigger with an EventBridge rule, and automating deployment with GitHub Actions.

The tutorial also includes a diagram of the app's architecture and code snippets for each step.