Ada for bigger projects, D for quick one-offs and more “scripty” work.
there was some Russian dev running a systems tech company, I forget his name, living in Thailand, like in koh samui or similar place. he used D for his work, which was software products. came across him on the net. I saw a couple of his posts about D.
one was titled, why D, and the other was, D as a scripting language.
I thought both were good.
I did, a quick thought, regarding https://github.com/docandrew/SPARKTLS: you might find https://github.com/Componolit/libsparkcrypto useful, too, if you have not already.
Nice projects BTW!