JavaScript plays a powerful role in creating rich interactive experiences. But its power comes at a cost: longer load times, sluggish pages, and inaccessible content. The more we rely on client-side rendering, the more likely we are to exclude visitors with older devices, slower connections, or those who have disabled JavaScript altogether. If we want people to fully experience the sites we have worked so hard to craft, then we must be judicious in our use of JavaScript. In thoughtful detail, Jeremy Wagner shows how JavaScript can be used to progressively enhance server-side functionality, while improving speed and access for more visitors. By centering user needs every step of the way-from toolchains to metrics to testing-we can all contribute to a more inclusive, accessible, and resilient web. THIS BOOK EXPLORES: How framework choices directly impact user experience outcomes Techniques for loading JavaScript and effectively navigating modern toolchains How to mitigate performance disruption from third-party JavaScript Using Service Worker technology to create more resilient experiences