Indeed, I did ever worked. Of course you need some breadth of knowledge, but unless the place was absolutely tiny, your low-level developers writing VHDL weren

Indeed, I did ever worked. Of course you need some breadth of knowledge, but unless the place was absolutely tiny, your low-level developers writing VHDL weren't going to be asked to optimize a SQL query or tweak CSS. Not that they couldn't, but why would you?