Hi Na'aman! I didn't use any c++ for developing Sia, it's just JS, and it's already faster than the other Node.js serialization libraries that use c++ or wasm.

I've investigated using webassembly or c++, however, there's an overhead when passing values from JS to wasm/native, and in the end using wasm just made the serialization slower.

In fact, the reason Sia is so fast is because we're removing such overheads when serializing shorter strings.