Sending a SMS from a Gatsby website using Twilio Serverless Functions and React is now possible as explained in this tutorial. The JAMstack, which stands for JavaScript, APIs, and Markup, is a performance-boosting approach to building websites that uses static site generators instead of dynamic HTML generation. Gatsby bridges the gap between JAMstack static sites and traditional web apps by compiling React components into HTML plus a little bit of JavaScript to support user interactivity. The tutorial starts with setting up a new Gatsby project, adding an SMS form to the default starter, and modifying it to make a request to a serverless function. A Twilio serverless function is created to handle the SMS sending functionality, which is then integrated into the SMSForm component. The tutorial concludes by explaining how to send a message using the newly created form.