Can’t edit the post anymore, but just wanted to bring some informations about the render stuff.
It is possible to split the views used by a controller in multiples files, despite the mentionned mapping in the Phoenix documentation (CF second update of the earlier post). The thing is, your conn will automatically try to reach your default view (named after your controller) when calling render in said controller. However, using the put_view function in a pattern allow you to manually set the view file used by the pattern.
Ex:
render(conn, "index.json", examens: examens) # Use default view
# Can become :
conn
|> put_view(ExamenSecondView) # Replace the default associated view in plug
|> render("index.json", examens: examens) # Use index from second view