application.ex

defmodule ElixirContainerAgentExperiment.Application do
  use Application

  def start(_type, _args) do
    children = [
      {
        Task.Supervisor,
        name: ElixirContainerAgentExperiment.ExampleSupervisor
      }
    ]

    opts = [strategy: :one_for_one, name: ElixirContainerAgentExperiment.Supervisor]
    Supervisor.start_link(children, opts)
  end
end

elixir_container_agent_experiment.ex

defmodule ElixirContainerAgentExperiment do
  require Logger

  def hello do
    Logger.info("Starting outer")
    Task.Supervisor.async(ElixirContainerAgentExperiment.ExampleSupervisor, fn () ->
      Logger.info("Starting inner")
      :ok = Process.sleep(30000 * 3)
      Logger.info("Finishing inner")
    end)
    Logger.info("Continuing outer")
    :ok = Process.sleep(30000)
    Logger.info("Finishing outer")
  end
end

elixir_container_agent_experiment.example_supervisor.ex

defmodule ElixirContainerAgentExperiment.ExampleSupervisor do

end