[mipsmaster]

Unlike Dropwizard, it is really intended for an asynchronous model of development. You don't have to worry about pushing the concurrency limits of an OS by starting thousands of threads if your application has a high ratio of callouts (disk, network IO) to computation (CPU), as is common with a lot of microservices. I guess this approach works best if your app's dependencies are convenient for asynchronous calls as well - HTTP, Cassandra, etc.

[pron]

There's no need for asynchronous code and new frameworks to achieve that. Comsat makes Dropwizard run simple blocking requests in Quasar fibers (I'm a Quasar/Comsat dev), so you get all the performance of async code while still working with simple blocking code, standard APIs (JAX-RS), and standard servers (Jetty). You can easily run a hundreds-of-thousands if not millions of fibers in a single JVM without getting into trouble.