It seems to be the new trend : building "boxes" based on raspberry pi, including sensors to mesure any sort of thing, and sending data to a REST API.

Was contacted for a project like this, to make the backend for the project.
I ask to the client the credentials of the dev who will makes the embedded dev, to know the format of data I will receive and send to the "box", the client respond that "I don't need to know that", and, besides, they don't have any dev for this post for now, but I can begin the dev for the backend without that, not knowing data structure, and will receive all of that for half December, for a deadline in early January.

Tell the client that his project will never be done in the deadline, got ejected from the project, client is pretty sure he will find à dev who will do all the work in 2 weeks.

Fuckin' startup culture.