The author of the text is a fan of their Elgato Stream Deck and wants to use it to trigger a site build on Netlify at the press of a button. To achieve this, they create a serverless function that checks for a specific query parameter in the URL, and if it matches, makes a POST request to the Netlify build hook URL, triggering a site build. The author sets up two environment variables - DEPLOY_ME_URL and DEPLOY_ME_SECRET - to secure the deployment mechanism and adds them to their Netlify project. They then create a new serverless function in JavaScript that uses node-fetch to make the POST request to the build hook URL if the secret parameter matches, or returns an error response otherwise. The author sets up a Stream Deck button with the function's URL and secret parameter, allowing them to trigger a site build by clicking the button.