I believe Cisco has used Scheme, having bought the Chez Scheme company (then in 2016 open-sourcing Chez). I've also seen a blog/twitter post from a Cisco guy a

I believe Cisco has used Scheme, having bought the Chez Scheme company (then in 2016 open-sourcing Chez). I've also seen a blog/twitter post from a Cisco guy about Clojure.