> Even for the parts that are being compiled to JS: You wouldn't say: You can not have C++ in production, only binaries.

I would say that because it can be decompiled; the type information is still present. Same with C#. I can decompile the binary and still see the type information.

The process of going from TS to JS is lossy; you cannot get back the type information.

I would absolutely say "I have C++ in production" or "I have C# in production" but not say "I have TypeScript in production". "We build our app with TypeScript" is accurate, but it is transpiled -- not compiled -- into JavaScript. Your Node.js server then interprets that JavaScript and executes C++.

That is not right, When you compile to binaries, you do type erasure in CPP, som of the stuff can not be reconstructed or inferred, especially when using o flags.

JS -> TS is easy, you just re-anotate with `: any` everywhere.

Anyways, you are word juggling now.

Type definitions are definitely compiled with CPP. Type erasure only happens with polymorphism types. You can actually view the types with ghidra.

> Your Node.js server then interprets that JavaScript and executes C++.

Umm...no? V8 specifically compiles it into machine code directly.

There used to be a pseudo-translation layer in the CrankShaftScript days, but that hasn't been true in almost a decade.

> I can decompile the binary and still see the type information.

Also no. The de-compiler can _infer_ the types, much like how V8 tries to infer the type. But the actual type information is gone.

Even in languages like Java where most of the type information is preserved, some things are still lost (e.g. generic methods with dynamicinvoke)