> From my superficial knowledge of compilers, "modularization" itself should not make code faster, if anything slower. There'll always be some overhead of loadi

> From my superficial knowledge of compilers, "modularization" itself should not make code faster, if anything slower. There'll always be some overhead of loading modules and communicating between them, not? I think this is a misunderstanding of what actually happened. TypeScript has a thing called “namespaces” and a thing called “modules”. Both provide modularization. The TS repo is not being modularized, instead, the namespaces are getting converted to modules. Namespaces are an old-school approach to writing a module in JavaScript. You pack all of your exports into a JS object, and then access the object from somewhere else. This works, but JS is dynamic, and the runtime has no way to guarantee that you won’t mess with this object (replace functions or whatnot). Modules don’t have this object. You just call the function, instantiate the class, or do whatever else with the names you imported. They are resolved statically, so certain optimizations become more “obvious”, like inlining.