Storing files directly on the server where the Dolittle bounded-context runs is not what I’d usually recommend. That is, assuming you’re running in our hosted environment. If you’re running it on your own hardware or some other setup your setting may be different.
The bounded-context is an application that runs in a docker container. This docker container is a docker image, and the state that has been made since it was started. There is usually no direct guarantee that the container will be stored - i.e. the container may go away and a new one will be set up from the docker image. This means that any files you store where your bounded context runs may not be persisted.
To persist files I recommend sending them to something that will guarantee persistence (like Azure Blob Storage or similar).