I adore Elixir and have made a good career around it. I'll love it until my grave.

But with that many servers I can't help but wonder if Rust wouldn't be a better choice. I don't think they'll even need 100 which, as OP pointed out, will drastically reduce their operational complexity.

Furthermore, the strong static typing would have avoided the megamorphic functions right from the start.

Yeah I agree with rust, I have some simple database fetching servers that run crypto functions as well (I.e. login) and for simpler operations they can quickly get to 100K+ requests per second on a single host