And good on them. But that doesn't mean it's easy to write large websites in dynamically-typed programming languages, it just means that they are very good at what they do.

No, it doesn't. It doesn't mean anything except that your belief isn't supported by any scientific data (as far as presented in this thread).

Let's see, each project usually has:

- Multi-site development at least in 3 countries; - Sometimes up to 100+ developers - CI systems - Source code of several MB of source code - Enterprise like infrastructures for Fortune 500 companies - Different skill sets from the "just out of the university" to the "top developer"

Maybe YouTube beats this, but Google only has Phd guys able to crack out crazy algorithms/data structures in minutes. Not typical in most software houses.

YouTube is of a different class of complexity as faced by enterprise developers integrating millions of lines of code across disparate systems.

And you have no idea how they struggled while developing it. Besides, it's not entirely written in python.

Enterprise world does not have the Phd developers that YouTube has.