The author built a headless Shopify e-commerce site with Next.js and shares their experience, including setting up a unified start to headless functionality. They used serverless functions to query the Shopify API and shared styles across projects for consistency. The author provides step-by-step instructions on how to set up Shopify and Next.js, including creating a development store, generating API credentials, and deploying the site. They also explain how to add serverless functions for the Shopify API, make pages for the site, and populate data using `getStaticProps` and `getStaticPaths`. The author concludes by encouraging readers to build their own headless Shopify stores with Next.js.