StaffJoy (https://www.staffjoy.com/) are using Julia for staff schedule optimization, and a large multinational is using it for train schedule optimization. Its also in use (at least on a trial basis) in the financial sector.

It'd still be a fairly large risk to develop something built-to-last on Julia at this point, so not really the best time for most companies to jump in unless something about Julia really solves a problem they are having.

I've seen a decent amount of chatter over the past year on the Julia mailing list from people integrating Julia into production. It's still in the beta stage, though, so risk-averse corporate users are generally being advised to hold tight until 1.0 is released. This (somewhat outdated) thread should give you some idea of where things are headed: https://groups.google.com/d/topic/julia-users/2mR24E0EtIg/di...

At the last Belgian Julia meetup there were 2 local companies present (10+ employees) that do all their development in Julia: http://www.tangent.works/ http://www.dynactionize.com/ I understand Blackrock has been sponsering the debugger work.