Decode JSON Nested Objects

You can use :jsn.as_map/1 (jsn | Hex)

~s(
      {
        "fields": {
          "summary": "Bug!",
          "issuetype": {
            "id": "10005"
          },
          "project": {
            "key": "BUG"
          },
          "description": {
            "type": "doc",
            "version": 1,
            "content": [
              {
                "type": "paragraph",
                "content": [
                  {
                    "text": "Description - Bug Found",
                    "type": "text"
                  }
                ]
              }
            ]
          }
        }
      }
    )
    |> Jason.decode! 
    |> :jsn.as_map
  end
%{
  "fields" => %{
    "description" => %{
      "content" => [
        %{
          "content" => [
            %{"text" => "Description - Bug Found", "type" => "text"}
          ],
          "type" => "paragraph"
        }
      ],
      "type" => "doc",
      "version" => 1
    },
    "issuetype" => %{"id" => "10005"},
    "project" => %{"key" => "BUG"},
    "summary" => "Bug!"
  }
}