> you can reason about each component in isolation
> you can focus on the explicit contracts between components
> you can design systems where problematic interactions are structurally impossible
In other words, exactly what a strong type system gives you?
My impression from doing my own amateurish hardware projects and knowing some real hardware engineers is that they would KILL for something like the type systems we have in software. In fact there are plenty of hardware description language projects that try to strengthen the type system of the HDL to catch errors early.
If you think a Rails test suite is bad, look at a Verilog test suite sometime.