Is Adhearsion slow because of Ruby?
The bottom line is Adhearsion will probably not be your bottleneck. Often, especially with Asterisk, it will be the telephony engine underneath Adhearsion that will be limiting your scaling. The servicing of a call with Adhearsion is almost always computationally simpler than serving even one page load with Ruby on Rails, with the main distinction that an Adhearsion call maintains a Thread and is a back-and-forth dialog, not one big textual response. That said, if you do experience Adhearsion to be a bottleneck, you can always scale it horizontally, balancing calls between Adhearsion instances. Because Adhearsion supports message queues and database integration, dealing with shared state between Adhearsion instances is extremely easy.
