Fair enough, threads are indeed cheaper than many realize, even JVM threads, which are basically OS threads. But projects where I use Scala do tend to include a

Fair enough, threads are indeed cheaper than many realize, even JVM threads, which are basically OS threads. But projects where I use Scala do tend to include a lot of service calls that are worth making concurrent (for example, hitting 3 services at once for a single request, or looking up 20 entities at once from a service that doesn’t have a bulk endpoint). And if you’re going to wrap this library with future calls, properly configure your threadpool, etc., you may as well have just used the very mature Play WS, and also get better efficiency. The APIs are pretty similar aside from Play WS returning Futures.