I'm not unrealistic - functional requirements are hardly ever complete, and they're almost always better than scalability and capacity planning.

Call me old fashioned, but I don't like messing around with production. I think you can reasonably scale down production environments and simulated wan networks packet loss/latency. I can't imagine a platform moderate importance not having some sort of benchmarking and scalability as part of their pre-prod pipeline automated acceptance criteria. It feels like this work would fall under that engineering role (again, performance test engineer or devops/sre).

Anyway, I think I chafe at the name more than anything. I know nonlinear dymanics, stress testing, queuing theory, et al and it just feels overly glib for what should be the most serious sort of activity a company considers.