I'm not sure how PHP integrates with common web servers today, because I've been pretty disconnected from that world for a decade, but at least you should be ab

I'm not sure how PHP integrates with common web servers today, because I've been pretty disconnected from that world for a decade, but at least you should be able to use the same mechanism to call the PHP runtime from your Node shim while keeping it alive. If PHP supports fastcgi, for example, there are modules in NPM that can do the Node side of it.