To deliver optimal user experience, web applications should have simple navigation and browsing, automatic resolution adjustment to suit the user (whether on mobile devices or desktop computers), minimal loading times, SEO, etc. All of these must be considered when designing a web application today. The Java/JEE ecosystem provides a number of frameworks that can facilitate the development of web applications, but have difficulties fulfilling the above-mentioned conditions. On the other hand , more and more web developers advocate “Single page” applications and JavaScript frameworks which boost development. How to take advantage of existing services (EJB) and introduce them into the world of JavaScript programming (JSON)? Should all data access be organized through an API?