Gatsby's default code-splitting mechanism often suffices for most development needs by intelligently dividing JavaScript bundles to optimize user experience, but issues can arise when using flexible layout components with heavy dependencies in a headless CMS. These components can inadvertently inflate bundle sizes because Gatsby's default configuration splits bundles by page-level, meaning all imports end up in the bundle regardless of actual use. To address this, the use of loadable-components is recommended, as it allows for fine-grained control over code-splitting, ensuring that only necessary components are included in the bundle, thus optimizing performance. This approach is particularly beneficial when components such as carousels are conditionally rendered, as it prevents unnecessary components from being loaded, enhancing page load times and maintaining server-side rendering (SSR). The implementation involves configuring loadable-components with a specific plugin to adjust the Webpack configuration for Gatsby, ensuring SSR is maintained, which is crucial to avoid any performance degradation that could outweigh the benefits of reduced bundle sizes.