I had a few endpoints that had to handle url parameters, query parameters, http headers and bodies which could either be json, form data or files, handling all

I had a few endpoints that had to handle url parameters, query parameters, http headers and bodies which could either be json, form data or files, handling all of those options using type annotated parameters ended up being pretty messy and I ended up just using the starlette request object. I was trying it out for a machine learning service that had to send back large dense vectors and I hit some other performance issues (like https://github.com/tiangolo/fastapi/issues/360#issuecomment-537690623 https://github.com/tiangolo/fastapi/issues/360#issuecomment-...), due to the coupling of validation with serialization.