I think that web applications are getting richer and richer in the browser, and server components are getting smaller. That is, the MVC pattern becomes more important in the browser, so this has led to minimizing the need to save and monitor the state on the server.
Thus, the most relevant issue is, perhaps, modern methods of creating web applications using Java, but rather modern methods of creating web applications in general. But if you want to focus only on the Java part, you'll see a shift from MVC more to REST-style data-centric services. Regardless of the fact that REST annotations in Spring MVC or a more โcleanโ JAX-RS implementation (and there are quite a lot of them), the small state that the server ends up supporting is a security context.
In terms of maximum scalability, which comes with the design and corresponding granularity of these data-oriented services. Of course, there are fundamentals on the server itself (shared resources, such as connection pools, thread pools, database tuning), but this is not something particularly new.
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