Customizing Open Graph metadata to improve the appearance of shared links on social media platforms can be achieved using Next.js, a static site builder. By adding programmatically customized `<meta>` tags to every page using the `next/head` component, developers can control the metadata displayed when sharing their content. This includes adding Open Graph tags such as `og:title`, `og:description`, and `og:image`, as well as Twitter-specific tags like `twitter:card` and `twitter:creator`. The use of static site builders allows for more flexibility in customizing metadata per page, unlike single-page applications which are restricted by their nature.