What survived the translation

Both versions had a router, a place to run code before the handler, a validation step, a serialisation step and an error path. That five-part shape is not a Node thing or a Python thing; it is what an HTTP service is. Learn it once and Go, Rust and Elixir become vocabulary problems rather than conceptual ones.

What did not survive is instructive too. Node is one thread running an event loop, so a synchronous loop over ten thousand items blocks every other request in flight. FastAPI on uvicorn runs async handlers on an event loop as well, but a blocking call inside an async def stalls the same way, while a plain def handler gets shunted to a thread pool. The failure modes are similar; the mechanisms that produce them are not.

The practical takeaway for hiring and for your own reading: job adverts list languages, but the interviews that matter test the shape. Being able to say why your auth check runs before your handler is worth more than knowing which decorator spells it.