Even a mediocre developer should be able to put together a workable prototype of a simple web app and/or API well within a single week, including setting up web servers, databases, and other basic infrastructure.

Experienced developers are often much faster and more efficient. This is especially true if they're using a language like Python that is quite suited to prototyping, and already offers so much pre-made functionality in the form of libraries and frameworks.

Many of us have learned to be very skeptical of these services that claim to allow software systems to be build rapidly. This often only holds true in a very, very small set of cases. Otherwise, the moment you try to do something unique or unusual, you'll hit one roadblock after another. It doesn't take long before the supposed "time-saving" or "effort-saving" service has wasted more time and effort than it would have taken to develop everything from scratch.

I just had this discussion with my friend today. While it is true that building a simple simple api from scratch is pretty quick, the hack-it-super-quickly api gets really hairy really quickly. Later you have to spend a lot of time refactoring to make the API scalable and easy to add endpoints and functionality. And usually you realize you have to refactor when the poop starts hitting the fan and the hacked together solution isn't holding its weight anymore.