"Scalable way" as defined by the platform Heroku was built and marketed for is single threaded. I won't argue that the lack of concurrency support in rails and

"Scalable way" as defined by the platform Heroku was built and marketed for is single threaded. I won't argue that the lack of concurrency support in rails and ruby is not also a stupid horrible unacceptable choice - and I never understood why the rails community defended it. Regardless, Heroku was originally built for and continues to market itself as a platform that can scale Rails by using intelligent routing, but it's quite clear that they can not. Maybe you understand the above, though it seems you are just trolling rails for being single-threaded. This is not the place.