It really depends on the project. My most recent project has been an attempt to revive some old ISDN videophones I bought and integrating them with a more moder

It really depends on the project. My most recent project has been an attempt to revive some old ISDN videophones I bought and integrating them with a more modern teleconference platform, so it involves all sorts of things, from whats basically a custom PBX to the video call app it will integrate with. For the core, PBX-like part, I was initially looking into Erlang, but after a while decided it might be easier to build on top of the JVM platform.