Hiring an AJAX Frameworks developer can significantly enhance your web application's user experience. They can create dynamic, interactive, and user-friendly interfaces that operate smoothly, increasing user engagement and satisfaction. Their expertise in AJAX allows seamless data exchange with the server, reducing the page loading time and making the application faster and more efficient. They can also help in building single-page applications that are easy to navigate, which can lead to improved customer retention rates. Additionally, they can ensure your website's compatibility across various browsers, enhancing accessibility and reach.