I assume these are mostly procedures, not functions, (that is, they have side effects) as applying a function 1.3M times per minute immediately raises the question of caching which doesn't seem to be important for them.

But if you execute that many procedure calls, how do you guard against them influencing each other due to their side effects? Memory leaks come to mind, or other weird bugs. Also, how do you manage the credentials to effectively issue side effects in a (hopefully) zero-trust environment?