Josh Comeau's blog post discusses the challenges and innovative solutions involved in building dynamic, interactive features on static sites, using the example of a Gatsby project called "Will it Build." This benchmarking service is designed to demonstrate how long it takes to build Gatsby sites with varying page counts and content sources. The team at Gatsby faced the problem of creating a dynamic filter without relying on a runtime API, which they resolved by using client-side navigation with Gatsby's Reach Router, maintaining a smooth user experience without the drawbacks of traditional route changes. By leveraging Gatsby's browser APIs, they preserved scroll positions and focus, and optimized URL structure to allow easy sharing of specific configurations. Comeau reflects on the trade-offs of their approach and suggests that as static sites gain popularity, more innovations in this area are expected, making web applications faster and easier to maintain.