[cess11]

What makes you think the BEAM VM is "heavy"?

It's almost like an OS in itself and initially designed to be like a more capable and robust OS on top of rather constrained computers. In my experience it's trivial to shell or port out to the environment when I want to, and I also see people that I don't think of as highly skilled low-level programmers do things with NIF:s so that can't be exceptionally demanding either.

[conradfr]

Yes it's definitely not heavy like a Java program that will cannibalize your RAM.

It's actually quite lean.

It will use all your cores without you asking (which is fantastic right?) but it's configurable AFAIK.

[cess11]

It will also use preemptive multitasking, so busy processes won't pin CPU cores at the expense of other tasks.