diff --git a/config/releases.exs b/config/releases.exs
index fa3cd5dd..498ee975 100644
--- a/config/releases.exs
+++ b/config/releases.exs
@@ -5,7 +5,7 @@ config :teslamate, TeslaMate.Repo,
   password: System.fetch_env!("DATABASE_PASS"),
   database: System.fetch_env!("DATABASE_NAME"),
   hostname: System.fetch_env!("DATABASE_HOST"),
-  pool_size: 15
+  pool_size: System.get_env("DATABASE_POOL_SIZE", "15") |> String.to_integer()
 
 config :teslamate, TeslaMateWeb.Endpoint,
   http: [:inet6, port: System.get_env("PORT", "4000")],
@@ -19,28 +19,27 @@ config :teslamate, :tesla_auth,
   username: System.fetch_env!("TESLA_USERNAME"),
   password: System.fetch_env!("TESLA_PASSWORD")
 
-config :teslamate, :mqtt,
-  host: System.fetch_env!("MQTT_HOST"),
-  username: System.fetch_env!("MQTT_USERNAME"),
-  password: System.fetch_env!("MQTT_PASSWORD")
+if System.get_env("DISABLE_MQTT") != "true" do
+  config :teslamate, :mqtt,
+    host: System.fetch_env!("MQTT_HOST"),
+    username: System.fetch_env!("MQTT_USERNAME"),
+    password: System.fetch_env!("MQTT_PASSWORD")
+end
 
 config :logger,
-  backends: [LoggerTelegramBackend, :console],
   level: :info,
-  handle_otp_reports: true,
-  handle_sasl_reports: false,
-  compile_time_purge_level: :info
+  compile_time_purge_matching: [[level_lower_than: :info]]
 
 config :logger, :console,
   format: "$time $metadata[$level] $message\n",
   metadata: []
 
-config :logger, :telegram,
-  level: :error,
-  chat_id: System.fetch_env!("CHAT_ID"),
-  token: System.fetch_env!("TOKEN")
+if System.get_env("ENABLE_LOGGER_TELEGRAM") == "true" do
+  config :logger,
+    backends: [LoggerTelegramBackend, :console]
 
-config :teslamate, :mqtt,
-  host: System.fetch_env!("MQTT_HOST"),
-  username: System.fetch_env!("MQTT_USERNAME"),
-  password: System.fetch_env!("MQTT_PASSWORD")
+  config :logger, :telegram,
+    level: :error,
+    chat_id: System.fetch_env!("CHAT_ID"),
+    token: System.fetch_env!("TOKEN")
+end
diff --git a/lib/teslamate/api.ex b/lib/teslamate/api.ex
index 8e62e2a5..a42b7bd9 100644
--- a/lib/teslamate/api.ex
+++ b/lib/teslamate/api.ex
@@ -39,7 +39,8 @@ defmodule TeslaMate.Api do
   # Callbacks
 
   @impl true
-  def init(opts) do
+  def init(_opts) do
+    opts = Application.fetch_env!(:teslamate, :tesla_auth)
     username = Keyword.fetch!(opts, :username)
     password = Keyword.fetch!(opts, :password)
 
diff --git a/lib/teslamate/application.ex b/lib/teslamate/application.ex
index 2d0cf8a4..3da0e3e6 100644
--- a/lib/teslamate/application.ex
+++ b/lib/teslamate/application.ex
@@ -1,21 +1,18 @@
 defmodule TeslaMate.Application do
-  # See https://hexdocs.pm/elixir/Application.html
-  # for more information on OTP Applications
   @moduledoc false
 
   use Application
 
   def start(_type, _args) do
-    children = [
+    [
       TeslaMate.Repo,
       TeslaMateWeb.Endpoint,
-      TeslaMateWeb.Presence,
-      {TeslaMate.Api, auth()},
+      TeslaMate.Api,
       TeslaMate.Vehicles,
-      TeslaMate.Mqtt
+      if(enable_mqtt, do: TeslaMate.Mqtt)
     ]
-
-    Supervisor.start_link(children, strategy: :one_for_one, name: TeslaMate.Supervisor)
+    |> Enum.reject(&is_nil/1)
+    |> Supervisor.start_link(strategy: :one_for_one, name: TeslaMate.Supervisor)
   end
 
   # Tell Phoenix to update the endpoint configuration
@@ -25,8 +22,5 @@ defmodule TeslaMate.Application do
     :ok
   end
 
-  # TODO move into Api (get_lazy)
-  defp auth do
-    Application.get_env(:teslamate, :tesla_auth)
-  end
+  defp enable_mqtt, do: !is_nil(Application.get_env(:teslamate, :mqtt))
 end