Most backend frameworks can just route new requests to the updated code - so a refresh is all you need (though there are tools that simply make that refresh automatic, which is pretty much how js frameworks work as well. Intellij can also make the whole recompile-replace code function happen on window defocus, so by the time you switch to your browser, it is already refreshed. And nowadays the compile of something like Java can well be faster than whatever that npm monstrosity does)