[derefr]

I believe that the reason they switched away from Erlang, though, was that nearly nobody in the company (besides the team that made the prototype) knew the language. In other words, they switched away because they had trouble integrating Erlang into their processes, and instead chose to rewrite it using tools everyone else was more familiar with.

This, then, is basically recreating the same problem they had before, just with 40 or so more engineers who are on the "Erlang" side of the vote.

[pessimizer]

Yariv Sadan is already there, though. That plus the WhatsApp people makes for a pretty intimidating group of erlangers.

edit: Just found out Yariv left. Still, Facebook was using ejabberd, and WhatsApp built their business around ejabberd.