In this blog post, the author discusses how to add user reactions to Gatsby blog posts using a React UI component called react-svg-bubble-slider. The author explains that adding reactions removes the need for moderation and allows users to choose from a pre-approved set of reactions. They also explain how to get started with integrating react-svg-bubble-slider into a Gatsby project, including importing the component, configuring icons, getting current reaction, mapping over state values, and handling user interaction when buttons are clicked. The author provides an example code snippet that demonstrates this process, which includes storing count values in local state and updating them on button clicks. Finally, they mention using FaunaDB to store reaction counts in a real-world scenario.