Init project.

lib/link_shortener/application.ex

@@ -0,0 +1,36 @@
+defmodule LinkShortener.Application do
+  # See https://hexdocs.pm/elixir/Application.html
+  # for more information on OTP Applications
+  @moduledoc false
+
+  use Application
+
+  @impl true
+  def start(_type, _args) do
+    children = [
+      # Start the Ecto repository
+      LinkShortener.Repo,
+      # Start the Telemetry supervisor
+      LinkShortenerWeb.Telemetry,
+      # Start the PubSub system
+      {Phoenix.PubSub, name: LinkShortener.PubSub},
+      # Start the Endpoint (http/https)
+      LinkShortenerWeb.Endpoint
+      # Start a worker by calling: LinkShortener.Worker.start_link(arg)
+      # {LinkShortener.Worker, arg}
+    ]
+
+    # See https://hexdocs.pm/elixir/Supervisor.html
+    # for other strategies and supported options
+    opts = [strategy: :one_for_one, name: LinkShortener.Supervisor]
+    Supervisor.start_link(children, opts)
+  end
+
+  # Tell Phoenix to update the endpoint configuration
+  # whenever the application is updated.
+  @impl true
+  def config_change(changed, _new, removed) do
+    LinkShortenerWeb.Endpoint.config_change(changed, removed)
+    :ok
+  end
+end

lib/link_shortener/mailer.ex

@@ -0,0 +1,3 @@
+defmodule LinkShortener.Mailer do
+  use Swoosh.Mailer, otp_app: :link_shortener
+end

lib/link_shortener/repo.ex

@@ -0,0 +1,5 @@
+defmodule LinkShortener.Repo do
+  use Ecto.Repo,
+    otp_app: :link_shortener,
+    adapter: Ecto.Adapters.Postgres
+end