I've seen a single company that does warehouse management software out of Sweden that advertises (in job listings) that they're using it. Otherwise, it's pretty slim pickings if you're not applying in its wheelhouse (high integrity systems -- aerospace, defense, medical, etc).
If you do microcontroller firmware development, I'd say it's perfectly reasonable to float it for a smaller project and just give it a spin. The language is significantly more modern/sane than C so you're not really exposing yourself to much talent risk. There's no gaping holes in the environment, experienced firmware devs will adjust easily, and new devs will feel more at home with the facilities provided.
Probably more jobs available for language VHDL (influenced by Ada) than Ada itself. Of course as a hardware description language you're on the hardware side of things. Also, worth noting it's more popular in Europe (Verilog seems to have won over in the US).
I have been out of the defense industry for quite a while now, but even back then, more and more projects were using C/C++, because it was so hard to hire Ada developers.
If you do microcontroller firmware development, I'd say it's perfectly reasonable to float it for a smaller project and just give it a spin. The language is significantly more modern/sane than C so you're not really exposing yourself to much talent risk. There's no gaping holes in the environment, experienced firmware devs will adjust easily, and new devs will feel more at home with the facilities provided.