Elixir Convention for Error Handling with decent User Experience

application.ex

defmodule Application do
  def get_queue_url() do
    url = Application.get_env(:dau, RabbitMQ) |> Keyword.get(:urls)
    case url do
      url -> {:ok, url}
      nil -> {:error, "Queue URL is not set"}
    end
  rescue
    _ -> {:error, "Unexpected Error : Fetching Queue URL"}
  end
end

context.ex

defmodule Job do
  def add(attrs) do
    with {:ok, job} <- JobRequest.new(attrs),
         {:ok, url} <- Application.get_queue_url(),
         {:ok, conn} <- Connection.open(url),
         {:ok, channel} <- Channel.open(conn),
         {:ok, response} <- Queue.add(channel, job) do
      {:ok, response}
    else
      {:error, reason} -> {:error, "Unable to add job : #{inspect(reason)}"}
    end
  rescue
    _ -> {:error, "Malformed Request"}
  end
end