diff --git a/apps/ethereum_jsonrpc/mix.exs b/apps/ethereum_jsonrpc/mix.exs
index 2984527c8c..cdd6428a9d 100644
--- a/apps/ethereum_jsonrpc/mix.exs
+++ b/apps/ethereum_jsonrpc/mix.exs
@@ -38,7 +38,11 @@ defmodule EthereumJsonrpc.MixProject do
   end
 
   defp aliases(env) do
-    env_aliases(env)
+    [
+      # to match behavior of `mix test` from project root, which needs to not start applications for `indexer` to
+      # prevent its supervision tree from starting, which is undesirable in test
+      test: "test --no-start"
+    ] ++ env_aliases(env)
   end
 
   defp env_aliases(:dev), do: []
diff --git a/apps/ethereum_jsonrpc/test/test_helper.exs b/apps/ethereum_jsonrpc/test/test_helper.exs
index 9fbe8ddc4c..1a944da0e7 100644
--- a/apps/ethereum_jsonrpc/test/test_helper.exs
+++ b/apps/ethereum_jsonrpc/test/test_helper.exs
@@ -3,5 +3,8 @@ junit_folder = Mix.Project.build_path() <> "/junit/#{Mix.Project.config()[:app]}
 File.mkdir_p!(junit_folder)
 :ok = Application.put_env(:junit_formatter, :report_dir, junit_folder)
 
+# Counter `test --no-start`.  `--no-start` is needed for `:indexer` compatibility
+{:ok, _} = Application.ensure_all_started(:ethereum_jsonrpc)
+
 ExUnit.configure(formatters: [JUnitFormatter, ExUnit.CLIFormatter])
 ExUnit.start()
diff --git a/apps/explorer/config/config.exs b/apps/explorer/config/config.exs
index 623aa3b946..623945f5c5 100644
--- a/apps/explorer/config/config.exs
+++ b/apps/explorer/config/config.exs
@@ -7,10 +7,6 @@ use Mix.Config
 
 config :ecto, json_library: Jason
 
-config :explorer, :indexer,
-  block_rate: 5_000,
-  debug_logs: !!System.get_env("DEBUG_INDEXER")
-
 # General application configuration
 config :explorer,
   ecto_repos: [Explorer.Repo],
diff --git a/apps/explorer/lib/explorer/application.ex b/apps/explorer/lib/explorer/application.ex
index 777bbce359..9d3f8a5ce7 100644
--- a/apps/explorer/lib/explorer/application.ex
+++ b/apps/explorer/lib/explorer/application.ex
@@ -25,7 +25,6 @@ defmodule Explorer.Application do
     [
       configure(Explorer.Chain.Statistics.Server),
       configure(Explorer.ExchangeRates),
-      configure(Explorer.Indexer.Supervisor),
       configure(Explorer.Market.History.Cataloger)
     ]
     |> List.flatten()
diff --git a/apps/explorer/mix.exs b/apps/explorer/mix.exs
index 9de0741f62..45f64f8110 100644
--- a/apps/explorer/mix.exs
+++ b/apps/explorer/mix.exs
@@ -75,8 +75,6 @@ defmodule Explorer.Mixfile do
       # Code coverage
       {:excoveralls, "~> 0.8.1", only: [:test]},
       {:exvcr, "~> 0.10", only: :test},
-      # JSONRPC access to Parity for `Explorer.Indexer`
-      {:ethereum_jsonrpc, in_umbrella: true},
       {:httpoison, "~> 1.0", override: true},
       {:jason, "~> 1.0"},
       {:junit_formatter, ">= 0.0.0", only: [:test], runtime: false},
@@ -100,7 +98,7 @@ defmodule Explorer.Mixfile do
     [
       "ecto.setup": ["ecto.create", "ecto.migrate", "run priv/repo/seeds.exs"],
       "ecto.reset": ["ecto.drop", "ecto.setup"],
-      test: ["ecto.create --quiet", "ecto.migrate", "test"]
+      test: ["ecto.create --quiet", "ecto.migrate", "test --no-start"]
     ] ++ env_aliases(env)
   end
 
diff --git a/apps/explorer/test/test_helper.exs b/apps/explorer/test/test_helper.exs
index df5634fd24..8730cafb4d 100644
--- a/apps/explorer/test/test_helper.exs
+++ b/apps/explorer/test/test_helper.exs
@@ -3,6 +3,9 @@ junit_folder = Mix.Project.build_path() <> "/junit/#{Mix.Project.config()[:app]}
 File.mkdir_p!(junit_folder)
 :ok = Application.put_env(:junit_formatter, :report_dir, junit_folder)
 
+# Counter `test --no-start`.  `--no-start` is needed for `:indexer` compatibility
+{:ok, _} = Application.ensure_all_started(:explorer)
+
 ExUnit.configure(formatters: [JUnitFormatter, ExUnit.CLIFormatter])
 ExUnit.start()
 
diff --git a/apps/explorer_web/mix.exs b/apps/explorer_web/mix.exs
index cf5bc140bc..b395cde13e 100644
--- a/apps/explorer_web/mix.exs
+++ b/apps/explorer_web/mix.exs
@@ -112,7 +112,13 @@ defmodule ExplorerWeb.Mixfile do
       compile: "compile --warnings-as-errors",
       "ecto.setup": ["ecto.create", "ecto.migrate", "run priv/repo/seeds.exs"],
       "ecto.reset": ["ecto.drop", "ecto.setup"],
-      test: ["ecto.create --quiet", "ecto.migrate", "test"]
+      test: [
+        "ecto.create --quiet",
+        "ecto.migrate",
+        # to match behavior of `mix test` from project root, which needs to not start applications for `indexer` to
+        # prevent its supervision tree from starting, which is undesirable in test
+        "test --no-start"
+      ]
     ]
   end
 
diff --git a/apps/explorer_web/test/test_helper.exs b/apps/explorer_web/test/test_helper.exs
index f58ef1f9d1..0c8e8846e2 100644
--- a/apps/explorer_web/test/test_helper.exs
+++ b/apps/explorer_web/test/test_helper.exs
@@ -3,12 +3,15 @@ junit_folder = Mix.Project.build_path() <> "/junit/#{Mix.Project.config()[:app]}
 File.mkdir_p!(junit_folder)
 :ok = Application.put_env(:junit_formatter, :report_dir, junit_folder)
 
-ExUnit.configure(formatters: [JUnitFormatter, ExUnit.CLIFormatter])
-ExUnit.start()
+# Counter `test --no-start`.  `--no-start` is needed for `:indexer` compatibility
+{:ok, _} = Application.ensure_all_started(:explorer_web)
 
 {:ok, _} = Application.ensure_all_started(:wallaby)
 Application.put_env(:wallaby, :base_url, ExplorerWeb.Endpoint.url())
 
 {:ok, _} = Application.ensure_all_started(:ex_machina)
 
+ExUnit.configure(formatters: [JUnitFormatter, ExUnit.CLIFormatter])
+ExUnit.start()
+
 Ecto.Adapters.SQL.Sandbox.mode(Explorer.Repo, :manual)
diff --git a/apps/indexer/config/config.exs b/apps/indexer/config/config.exs
index e1d88eb57c..7999d8e40e 100644
--- a/apps/indexer/config/config.exs
+++ b/apps/indexer/config/config.exs
@@ -2,29 +2,8 @@
 # and its dependencies with the aid of the Mix.Config module.
 use Mix.Config
 
-# This configuration is loaded before any dependency and is restricted
-# to this project. If another project depends on this project, this
-# file won't be loaded nor affect the parent project. For this reason,
-# if you want to provide default values for your application for
-# 3rd-party users, it should be done in your "mix.exs" file.
+config :indexer,
+  block_rate: 5_000,
+  debug_logs: !!System.get_env("DEBUG_INDEXER")
 
-# You can configure your application as:
-#
-#     config :indexer, key: :value
-#
-# and access this configuration in your application as:
-#
-#     Application.get_env(:indexer, :key)
-#
-# You can also configure a 3rd-party app:
-#
-#     config :logger, level: :info
-#
-
-# It is also possible to import configuration files, relative to this
-# directory. For example, you can emulate configuration per environment
-# by uncommenting the line below and defining dev.exs, test.exs and such.
-# Configuration from the imported file will override the ones defined
-# here (which is why it is important to import them last).
-#
-#     import_config "#{Mix.env}.exs"
+config :indexer, ecto_repos: [Explorer.Repo]
diff --git a/apps/indexer/lib/indexer.ex b/apps/indexer/lib/indexer.ex
index 8f82749472..80e8bdc7cf 100644
--- a/apps/indexer/lib/indexer.ex
+++ b/apps/indexer/lib/indexer.ex
@@ -1,10 +1,10 @@
-defmodule Explorer.Indexer do
+defmodule Indexer do
   @moduledoc """
   Indexes an Ethereum-based chain using JSONRPC.
   """
   require Logger
 
-  alias Explorer.{Chain, Indexer}
+  alias Explorer.Chain
 
   @doc """
   The maximum `t:Explorer.Chain.Block.t/0` `number` that was indexed
@@ -13,12 +13,12 @@ defmodule Explorer.Indexer do
 
       iex> insert(:block, number: 2)
       iex> insert(:block, number: 1)
-      iex> Explorer.Indexer.max_block_number()
+      iex> Indexer.max_block_number()
       2
 
   If there are no blocks, `0` is returned to indicate to index from genesis block.
 
-      iex> Explorer.Indexer.max_block_number()
+      iex> Indexer.max_block_number()
       0
 
   """
@@ -34,16 +34,16 @@ defmodule Explorer.Indexer do
 
   When there are no blocks the next block is the 0th block
 
-      iex> Explorer.Indexer.max_block_number()
+      iex> Indexer.max_block_number()
       0
-      iex> Explorer.Indexer.next_block_number()
+      iex> Indexer.next_block_number()
       0
 
   When there is a block, it is the successive block number
 
       iex> insert(:block, number: 2)
       iex> insert(:block, number: 1)
-      iex> Explorer.Indexer.next_block_number()
+      iex> Indexer.next_block_number()
       3
 
   """
@@ -69,14 +69,14 @@ defmodule Explorer.Indexer do
   Enables debug logs for indexing system.
   """
   def enable_debug_logs do
-    Application.put_env(:explorer, :indexer, Keyword.put(config(), :debug_logs, true))
+    Application.put_env(:indexer, :debug_logs, true)
   end
 
   @doc """
   Disables debug logs for indexing system.
   """
   def disable_debug_logs do
-    Application.put_env(:explorer, :indexer, Keyword.put(config(), :debug_logs, false))
+    Application.put_env(:indexer, :debug_logs, false)
   end
 
   @doc """
@@ -90,8 +90,6 @@ defmodule Explorer.Indexer do
   end
 
   defp debug_logs_enabled? do
-    Keyword.fetch!(config(), :debug_logs)
+    Application.fetch_env!(:indexer, :debug_logs)
   end
-
-  defp config, do: Application.fetch_env!(:explorer, :indexer)
 end
diff --git a/apps/indexer/lib/indexer/address_balance_fetcher.ex b/apps/indexer/lib/indexer/address_balance_fetcher.ex
index ae5e19186e..751fb46292 100644
--- a/apps/indexer/lib/indexer/address_balance_fetcher.ex
+++ b/apps/indexer/lib/indexer/address_balance_fetcher.ex
@@ -1,13 +1,13 @@
-defmodule Explorer.Indexer.AddressBalanceFetcher do
+defmodule Indexer.AddressBalanceFetcher do
   @moduledoc """
   Fetches `t:Explorer.Chain.Address.t/0` `fetched_balance`.
   """
 
   import EthereumJSONRPC, only: [integer_to_quantity: 1]
 
-  alias Explorer.{BufferedTask, Chain}
+  alias Explorer.Chain
   alias Explorer.Chain.{Block, Hash}
-  alias Explorer.Indexer
+  alias Indexer.BufferedTask
 
   @behaviour BufferedTask
 
@@ -16,7 +16,7 @@ defmodule Explorer.Indexer.AddressBalanceFetcher do
     max_batch_size: 500,
     max_concurrency: 4,
     init_chunk_size: 1000,
-    task_supervisor: Explorer.Indexer.TaskSupervisor
+    task_supervisor: Indexer.TaskSupervisor
   ]
 
   @doc """
diff --git a/apps/indexer/lib/indexer/address_extraction.ex b/apps/indexer/lib/indexer/address_extraction.ex
index 0bad95fc3b..729238a1ee 100644
--- a/apps/indexer/lib/indexer/address_extraction.ex
+++ b/apps/indexer/lib/indexer/address_extraction.ex
@@ -1,4 +1,4 @@
-defmodule Explorer.Indexer.AddressExtraction do
+defmodule Indexer.AddressExtraction do
   @moduledoc """
   Extract Addresses from data fetched from the Blockchain and structured as Blocks, InternalTransactions,
   Transactions and Logs.
@@ -104,7 +104,7 @@ defmodule Explorer.Indexer.AddressExtraction do
 
   Blocks have their `miner_hash` extracted.
 
-      iex> Explorer.Indexer.AddressExtraction.extract_addresses(
+      iex> Indexer.AddressExtraction.extract_addresses(
       ...>   %{
       ...>     blocks: [
       ...>       %{
@@ -124,7 +124,7 @@ defmodule Explorer.Indexer.AddressExtraction do
   Internal transactions can have their `from_address_hash`, `to_address_hash` and/or `created_contract_address_hash`
   extracted.
 
-      iex> Explorer.Indexer.AddressExtraction.extract_addresses(
+      iex> Indexer.AddressExtraction.extract_addresses(
       ...>   %{
       ...>     internal_transactions: [
       ...>       %{
@@ -161,7 +161,7 @@ defmodule Explorer.Indexer.AddressExtraction do
 
   Transactions can have their `from_address_hash` and/or `to_address_hash` extracted.
 
-      iex> Explorer.Indexer.AddressExtraction.extract_addresses(
+      iex> Indexer.AddressExtraction.extract_addresses(
       ...>   %{
       ...>     transactions: [
       ...>       %{
@@ -193,7 +193,7 @@ defmodule Explorer.Indexer.AddressExtraction do
 
   Logs can have their `address_hash` extracted.
 
-      iex> Explorer.Indexer.AddressExtraction.extract_addresses(
+      iex> Indexer.AddressExtraction.extract_addresses(
       ...>   %{
       ...>     logs: [
       ...>       %{
@@ -212,7 +212,7 @@ defmodule Explorer.Indexer.AddressExtraction do
 
   When the same address is mentioned multiple times, the greatest `block_number` is used
 
-      iex> Explorer.Indexer.AddressExtraction.extract_addresses(
+      iex> Indexer.AddressExtraction.extract_addresses(
       ...>   %{
       ...>     blocks: [
       ...>       %{
@@ -262,7 +262,7 @@ defmodule Explorer.Indexer.AddressExtraction do
   When a contract is created and then used in internal transactions and transaction in the same fetched data, the
   `created_contract_code` is merged with the greatest `block_number`
 
-      iex> Explorer.Indexer.AddressExtraction.extract_addresses(
+      iex> Indexer.AddressExtraction.extract_addresses(
       ...>   %{
       ...>     internal_transactions: [
       ...>       %{
diff --git a/apps/indexer/lib/indexer/application.ex b/apps/indexer/lib/indexer/application.ex
index 4ecdd6d6b5..318cbe5fb7 100644
--- a/apps/indexer/lib/indexer/application.ex
+++ b/apps/indexer/lib/indexer/application.ex
@@ -1,26 +1,24 @@
-defmodule Explorer.Indexer.Supervisor do
+defmodule Indexer.Application do
   @moduledoc """
-  Supervising the fetchers for the `Explorer.Indexer`
+  This is the `Application` module for `Indexer`.
   """
 
-  use Supervisor
+  use Application
 
-  alias Explorer.Indexer.{AddressBalanceFetcher, BlockFetcher, InternalTransactionFetcher, PendingTransactionFetcher}
+  alias Indexer.{AddressBalanceFetcher, BlockFetcher, InternalTransactionFetcher, PendingTransactionFetcher}
 
-  def start_link(opts) do
-    Supervisor.start_link(__MODULE__, opts, name: __MODULE__)
-  end
-
-  @impl Supervisor
-  def init(_opts) do
+  @impl Application
+  def start(_type, _args) do
     children = [
-      {Task.Supervisor, name: Explorer.Indexer.TaskSupervisor},
+      {Task.Supervisor, name: Indexer.TaskSupervisor},
       {AddressBalanceFetcher, name: AddressBalanceFetcher},
       {PendingTransactionFetcher, name: PendingTransactionFetcher},
       {InternalTransactionFetcher, name: InternalTransactionFetcher},
       {BlockFetcher, []}
     ]
 
-    Supervisor.init(children, strategy: :one_for_one)
+    opts = [strategy: :one_for_one, name: Indexer.Supervisor]
+
+    Supervisor.start_link(children, opts)
   end
 end
diff --git a/apps/indexer/lib/indexer/block_fetcher.ex b/apps/indexer/lib/indexer/block_fetcher.ex
index cebf0408ef..b696cdc7e2 100644
--- a/apps/indexer/lib/indexer/block_fetcher.ex
+++ b/apps/indexer/lib/indexer/block_fetcher.ex
@@ -1,4 +1,4 @@
-defmodule Explorer.Indexer.BlockFetcher do
+defmodule Indexer.BlockFetcher do
   @moduledoc """
   Fetches and indexes block ranges from gensis to realtime.
   """
@@ -7,12 +7,12 @@ defmodule Explorer.Indexer.BlockFetcher do
 
   require Logger
 
-  import Explorer.Indexer, only: [debug: 1]
+  import Indexer, only: [debug: 1]
 
   alias EthereumJSONRPC
   alias EthereumJSONRPC.Transactions
-  alias Explorer.{BufferedTask, Chain, Indexer}
-  alias Explorer.Indexer.{AddressBalanceFetcher, AddressExtraction, InternalTransactionFetcher, Sequence}
+  alias Explorer.Chain
+  alias Indexer.{AddressBalanceFetcher, AddressExtraction, BufferedTask, InternalTransactionFetcher, Sequence}
 
   # dialyzer thinks that Logger.debug functions always have no_local_return
   @dialyzer {:nowarn_function, import_range: 3}
@@ -63,7 +63,11 @@ defmodule Explorer.Indexer.BlockFetcher do
 
   @impl GenServer
   def init(opts) do
-    opts = Keyword.merge(Application.fetch_env!(:explorer, :indexer), opts)
+    opts =
+      :indexer
+      |> Application.get_all_env()
+      |> Keyword.merge(opts)
+
     :timer.send_interval(15_000, self(), :debug_count)
 
     state = %{
diff --git a/apps/indexer/lib/indexer/buffered_task.ex b/apps/indexer/lib/indexer/buffered_task.ex
index 523639acda..8e95c541d3 100644
--- a/apps/indexer/lib/indexer/buffered_task.ex
+++ b/apps/indexer/lib/indexer/buffered_task.ex
@@ -1,4 +1,4 @@
-defmodule Explorer.BufferedTask do
+defmodule Indexer.BufferedTask do
   @moduledoc """
   Provides a behaviour for batched task running with retries.
 
@@ -166,7 +166,7 @@ defmodule Explorer.BufferedTask do
            ]}
         ) :: {:ok, pid()} | {:error, {:already_started, pid()}}
   def start_link({module, base_opts}) do
-    default_opts = Application.fetch_env!(:explorer, :indexer)
+    default_opts = Application.get_all_env(:indexer)
     opts = Keyword.merge(default_opts, base_opts)
 
     GenServer.start_link(__MODULE__, {module, opts}, name: opts[:name])
diff --git a/apps/indexer/lib/indexer/internal_transaction_fetcher.ex b/apps/indexer/lib/indexer/internal_transaction_fetcher.ex
index b460aeea98..233f466ba4 100644
--- a/apps/indexer/lib/indexer/internal_transaction_fetcher.ex
+++ b/apps/indexer/lib/indexer/internal_transaction_fetcher.ex
@@ -1,4 +1,4 @@
-defmodule Explorer.Indexer.InternalTransactionFetcher do
+defmodule Indexer.InternalTransactionFetcher do
   @moduledoc """
   Fetches and indexes `t:Explorer.Chain.InternalTransaction.t/0`.
 
@@ -7,8 +7,8 @@ defmodule Explorer.Indexer.InternalTransactionFetcher do
 
   require Logger
 
-  alias Explorer.{BufferedTask, Chain, Indexer}
-  alias Explorer.Indexer.{AddressBalanceFetcher, AddressExtraction}
+  alias Explorer.Chain
+  alias Indexer.{AddressBalanceFetcher, AddressExtraction, BufferedTask}
   alias Explorer.Chain.{Block, Hash}
 
   @behaviour BufferedTask
@@ -20,7 +20,7 @@ defmodule Explorer.Indexer.InternalTransactionFetcher do
     max_concurrency: @max_concurrency,
     max_batch_size: @max_batch_size,
     init_chunk_size: 5000,
-    task_supervisor: Explorer.Indexer.TaskSupervisor
+    task_supervisor: Indexer.TaskSupervisor
   ]
 
   @doc """
diff --git a/apps/indexer/lib/indexer/pending_transaction_fetcher.ex b/apps/indexer/lib/indexer/pending_transaction_fetcher.ex
index 0fd03b934b..ba8b808f38 100644
--- a/apps/indexer/lib/indexer/pending_transaction_fetcher.ex
+++ b/apps/indexer/lib/indexer/pending_transaction_fetcher.ex
@@ -1,4 +1,4 @@
-defmodule Explorer.Indexer.PendingTransactionFetcher do
+defmodule Indexer.PendingTransactionFetcher do
   @moduledoc """
   Fetches pending transactions and imports them.
 
@@ -11,8 +11,8 @@ defmodule Explorer.Indexer.PendingTransactionFetcher do
 
   import EthereumJSONRPC.Parity, only: [fetch_pending_transactions: 0]
 
-  alias Explorer.{Chain, Indexer}
-  alias Explorer.Indexer.{AddressExtraction, PendingTransactionFetcher}
+  alias Explorer.Chain
+  alias Indexer.{AddressExtraction, PendingTransactionFetcher}
 
   # milliseconds
   @default_interval 1_000
@@ -46,8 +46,8 @@ defmodule Explorer.Indexer.PendingTransactionFetcher do
   @impl GenServer
   def init(opts) do
     opts =
-      :explorer
-      |> Application.fetch_env!(:indexer)
+      :indexer
+      |> Application.get_all_env()
       |> Keyword.merge(opts)
 
     state =
diff --git a/apps/indexer/lib/indexer/sequence.ex b/apps/indexer/lib/indexer/sequence.ex
index 08965945ae..6f7757673c 100644
--- a/apps/indexer/lib/indexer/sequence.ex
+++ b/apps/indexer/lib/indexer/sequence.ex
@@ -1,4 +1,4 @@
-defmodule Explorer.Indexer.Sequence do
+defmodule Indexer.Sequence do
   @moduledoc false
 
   use Agent
diff --git a/apps/indexer/mix.exs b/apps/indexer/mix.exs
index 93ba230ff4..676fde9f09 100644
--- a/apps/indexer/mix.exs
+++ b/apps/indexer/mix.exs
@@ -3,6 +3,7 @@ defmodule Indexer.MixProject do
 
   def project do
     [
+      aliases: aliases(),
       app: :indexer,
       version: "0.1.0",
       build_path: "../../_build",
@@ -10,6 +11,7 @@ defmodule Indexer.MixProject do
       deps_path: "../../deps",
       lockfile: "../../mix.lock",
       elixir: "~> 1.6",
+      elixirc_paths: elixirc_paths(Mix.env()),
       start_permanent: Mix.env() == :prod,
       deps: deps()
     ]
@@ -23,12 +25,25 @@ defmodule Indexer.MixProject do
     ]
   end
 
+  defp aliases do
+    [
+      # so that the supervision tree does not start, which would begin indexing, and so that the various fetchers can
+      # be started with `ExUnit`'s `start_supervised` for unit testing.
+      test: "test --no-start"
+    ]
+  end
+
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
-      # {:dep_from_hexpm, "~> 0.3.0"},
-      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"},
-      # {:sibling_app_in_umbrella, in_umbrella: true},
+      # JSONRPC access to Parity for `Explorer.Indexer`
+      {:ethereum_jsonrpc, in_umbrella: true},
+      # Importing to database
+      {:explorer, in_umbrella: true}
     ]
   end
+
+  # Specifies which paths to compile per environment.
+  defp elixirc_paths(:test), do: ["test/support" | elixirc_paths(:dev)]
+  defp elixirc_paths(_), do: ["lib"]
 end
diff --git a/apps/indexer/test/indexer/address_balance_fetcher_test.exs b/apps/indexer/test/indexer/address_balance_fetcher_test.exs
index 58d1cb2f96..e54bc0544d 100644
--- a/apps/indexer/test/indexer/address_balance_fetcher_test.exs
+++ b/apps/indexer/test/indexer/address_balance_fetcher_test.exs
@@ -1,10 +1,10 @@
-defmodule Explorer.Indexer.AddressBalanceFetcherTest do
+defmodule Indexer.AddressBalanceFetcherTest do
   # MUST be `async: false` so that {:shared, pid} is set for connection to allow AddressBalanceFetcher's self-send to have
   # connection allowed immediately.
   use Explorer.DataCase, async: false
 
   alias Explorer.Chain.{Address, Hash, Wei}
-  alias Explorer.Indexer.{AddressBalanceFetcher, AddressBalanceFetcherCase}
+  alias Indexer.{AddressBalanceFetcher, AddressBalanceFetcherCase}
 
   @block_number 2_932_838
   @hash %Explorer.Chain.Hash{
@@ -13,7 +13,7 @@ defmodule Explorer.Indexer.AddressBalanceFetcherTest do
   }
 
   setup do
-    start_supervised!({Task.Supervisor, name: Explorer.Indexer.TaskSupervisor})
+    start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
 
     :ok
   end
diff --git a/apps/indexer/test/indexer/address_extraction_test.exs b/apps/indexer/test/indexer/address_extraction_test.exs
index 3f9c788d66..29a822e6f9 100644
--- a/apps/indexer/test/indexer/address_extraction_test.exs
+++ b/apps/indexer/test/indexer/address_extraction_test.exs
@@ -1,13 +1,13 @@
-defmodule Explorer.Indexer.AddressExtractionTest do
+defmodule Indexer.AddressExtractionTest do
   use Explorer.DataCase, async: true
 
-  alias Explorer.Indexer.AddressExtraction
+  alias Indexer.AddressExtraction
 
   doctest AddressExtraction
 
   describe "extract_addresses/1" do
     test "blocks without a `miner_hash` aren't extracted" do
-      assert Explorer.Indexer.AddressExtraction.extract_addresses(%{
+      assert Indexer.AddressExtraction.extract_addresses(%{
                blocks: [
                  %{
                    number: 34
@@ -17,7 +17,7 @@ defmodule Explorer.Indexer.AddressExtractionTest do
     end
 
     test "blocks without a `number` aren't extracted" do
-      assert Explorer.Indexer.AddressExtraction.extract_addresses(%{
+      assert Indexer.AddressExtraction.extract_addresses(%{
                blocks: [
                  %{
                    miner_hash: "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca"
@@ -27,7 +27,7 @@ defmodule Explorer.Indexer.AddressExtractionTest do
     end
 
     test "internal_transactions with a `from_address_hash` without a `block_number` aren't extracted" do
-      assert Explorer.Indexer.AddressExtraction.extract_addresses(%{
+      assert Indexer.AddressExtraction.extract_addresses(%{
                internal_transactions: [
                  %{
                    from_address_hash: "0x0000000000000000000000000000000000000001"
@@ -37,7 +37,7 @@ defmodule Explorer.Indexer.AddressExtractionTest do
     end
 
     test "internal_transactions with a `to_address_hash` without a `block_number` aren't extracted" do
-      assert Explorer.Indexer.AddressExtraction.extract_addresses(%{
+      assert Indexer.AddressExtraction.extract_addresses(%{
                internal_transactions: [
                  %{
                    to_address_hash: "0x0000000000000000000000000000000000000002"
@@ -48,7 +48,7 @@ defmodule Explorer.Indexer.AddressExtractionTest do
 
     test "internal_transactions with a `created_contract_address_hash` and `created_contract_code` " <>
            "without a `block_number` aren't extracted" do
-      assert Explorer.Indexer.AddressExtraction.extract_addresses(%{
+      assert Indexer.AddressExtraction.extract_addresses(%{
                internal_transactions: [
                  %{
                    created_contract_address_hash: "0x0000000000000000000000000000000000000003",
@@ -59,7 +59,7 @@ defmodule Explorer.Indexer.AddressExtractionTest do
     end
 
     test "differing contract code is ignored" do
-      assert Explorer.Indexer.AddressExtraction.extract_addresses(%{
+      assert Indexer.AddressExtraction.extract_addresses(%{
                internal_transactions: [
                  %{
                    block_number: 1,
diff --git a/apps/indexer/test/indexer/block_fetcher_test.exs b/apps/indexer/test/indexer/block_fetcher_test.exs
index acdcc51c5b..82cf0f4ec2 100644
--- a/apps/indexer/test/indexer/block_fetcher_test.exs
+++ b/apps/indexer/test/indexer/block_fetcher_test.exs
@@ -1,16 +1,16 @@
-defmodule Explorer.Indexer.BlockFetcherTest do
+defmodule Indexer.BlockFetcherTest do
   # `async: false` due to use of named GenServer
   use Explorer.DataCase, async: false
 
   import ExUnit.CaptureLog
 
   alias Explorer.Chain.{Address, Block, Log, Transaction, Wei}
-  alias Explorer.Indexer
 
-  alias Explorer.Indexer.{
+  alias Indexer.{
     AddressBalanceFetcher,
     AddressBalanceFetcherCase,
     BlockFetcher,
+    BufferedTask,
     InternalTransactionFetcher,
     InternalTransactionFetcherCase,
     Sequence
@@ -46,7 +46,7 @@ defmodule Explorer.Indexer.BlockFetcherTest do
 
       assert Repo.aggregate(Block, :count, :hash) == 0
 
-      start_supervised!({Task.Supervisor, name: Explorer.Indexer.TaskSupervisor})
+      start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
       AddressBalanceFetcherCase.start_supervised!()
       InternalTransactionFetcherCase.start_supervised!()
       start_supervised!(BlockFetcher)
@@ -89,7 +89,7 @@ defmodule Explorer.Indexer.BlockFetcherTest do
     @tag :capture_log
     @heading "persisted counts"
     test "without debug_logs", %{state: state} do
-      start_supervised!({Task.Supervisor, name: Explorer.Indexer.TaskSupervisor})
+      start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
       AddressBalanceFetcherCase.start_supervised!()
       InternalTransactionFetcherCase.start_supervised!()
 
@@ -104,7 +104,7 @@ defmodule Explorer.Indexer.BlockFetcherTest do
 
     @tag :capture_log
     test "with debug_logs", %{state: state} do
-      start_supervised!({Task.Supervisor, name: Explorer.Indexer.TaskSupervisor})
+      start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
       AddressBalanceFetcherCase.start_supervised!()
       InternalTransactionFetcherCase.start_supervised!()
 
@@ -129,7 +129,7 @@ defmodule Explorer.Indexer.BlockFetcherTest do
     setup :state
 
     setup do
-      start_supervised!({Task.Supervisor, name: Explorer.Indexer.TaskSupervisor})
+      start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
       AddressBalanceFetcherCase.start_supervised!()
       InternalTransactionFetcherCase.start_supervised!()
       {:ok, state} = BlockFetcher.init([])
@@ -293,7 +293,7 @@ defmodule Explorer.Indexer.BlockFetcherTest do
 
   defp wait_for_tasks(buffered_task) do
     wait_until(5000, fn ->
-      counts = Explorer.BufferedTask.debug_count(buffered_task)
+      counts = BufferedTask.debug_count(buffered_task)
       counts.buffer == 0 and counts.tasks == 0
     end)
   end
diff --git a/apps/indexer/test/indexer/buffered_task_test.exs b/apps/indexer/test/indexer/buffered_task_test.exs
index 6e9e7ed261..228a8d1368 100644
--- a/apps/indexer/test/indexer/buffered_task_test.exs
+++ b/apps/indexer/test/indexer/buffered_task_test.exs
@@ -1,7 +1,7 @@
-defmodule Explorer.BufferedTaskTest do
+defmodule Indexer.BufferedTaskTest do
   use ExUnit.Case, async: true
 
-  alias Explorer.BufferedTask
+  alias Indexer.BufferedTask
 
   @max_batch_size 2
 
diff --git a/apps/indexer/test/indexer/internal_transaction_fetcher_test.exs b/apps/indexer/test/indexer/internal_transaction_fetcher_test.exs
index 0612e81a0f..8960545378 100644
--- a/apps/indexer/test/indexer/internal_transaction_fetcher_test.exs
+++ b/apps/indexer/test/indexer/internal_transaction_fetcher_test.exs
@@ -1,15 +1,15 @@
-defmodule Explorer.Indexer.InternalTransactionFetcherTest do
+defmodule Indexer.InternalTransactionFetcherTest do
   use Explorer.DataCase, async: false
 
   import ExUnit.CaptureLog
 
   alias Explorer.Chain.Transaction
-  alias Explorer.Indexer.{AddressBalanceFetcherCase, InternalTransactionFetcher, PendingTransactionFetcher}
+  alias Indexer.{AddressBalanceFetcherCase, InternalTransactionFetcher, PendingTransactionFetcher}
 
   @moduletag :capture_log
 
-  test "does not try to fetch pending transactions from Explorer.Indexer.PendingTransactionFetcher" do
-    start_supervised!({Task.Supervisor, name: Explorer.Indexer.TaskSupervisor})
+  test "does not try to fetch pending transactions from Indexer.PendingTransactionFetcher" do
+    start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
     AddressBalanceFetcherCase.start_supervised!()
     start_supervised!(PendingTransactionFetcher)
 
@@ -57,7 +57,7 @@ defmodule Explorer.Indexer.InternalTransactionFetcherTest do
 
   describe "run/2" do
     test "duplicate transaction hashes are logged" do
-      start_supervised!({Task.Supervisor, name: Explorer.Indexer.TaskSupervisor})
+      start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
       AddressBalanceFetcherCase.start_supervised!()
 
       insert(:transaction, hash: "0x03cd5899a63b6f6222afda8705d059fd5a7d126bcabe962fb654d9736e6bcafa")
@@ -82,7 +82,7 @@ defmodule Explorer.Indexer.InternalTransactionFetcherTest do
     end
 
     test "duplicate transaction hashes only retry uniques" do
-      start_supervised!({Task.Supervisor, name: Explorer.Indexer.TaskSupervisor})
+      start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
       AddressBalanceFetcherCase.start_supervised!()
 
       # not a real transaction hash, so that it fails
diff --git a/apps/indexer/test/indexer/pending_transaction_fetcher_test.exs b/apps/indexer/test/indexer/pending_transaction_fetcher_test.exs
index 0616827c1b..26b4496b75 100644
--- a/apps/indexer/test/indexer/pending_transaction_fetcher_test.exs
+++ b/apps/indexer/test/indexer/pending_transaction_fetcher_test.exs
@@ -1,16 +1,16 @@
-defmodule Explorer.Indexer.PendingTransactionFetcherTest do
+defmodule Indexer.PendingTransactionFetcherTest do
   # `async: false` due to use of named GenServer
   use Explorer.DataCase, async: false
 
   alias Explorer.Chain.Transaction
-  alias Explorer.Indexer.PendingTransactionFetcher
+  alias Indexer.PendingTransactionFetcher
 
   describe "start_link/1" do
     # this test may fail if Sokol so low volume that the pending transactions are empty for too long
     test "starts fetching pending transactions" do
       assert Repo.aggregate(Transaction, :count, :hash) == 0
 
-      start_supervised!({Task.Supervisor, name: Explorer.Indexer.TaskSupervisor})
+      start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
       start_supervised!(PendingTransactionFetcher)
 
       wait_for_results(fn ->
diff --git a/apps/indexer/test/indexer/sequence_test.exs b/apps/indexer/test/indexer/sequence_test.exs
index d01194d4c4..31334a34d1 100644
--- a/apps/indexer/test/indexer/sequence_test.exs
+++ b/apps/indexer/test/indexer/sequence_test.exs
@@ -1,7 +1,7 @@
-defmodule Explorer.Indexer.SequenceTest do
+defmodule Indexer.SequenceTest do
   use ExUnit.Case
 
-  alias Explorer.Indexer.Sequence
+  alias Indexer.Sequence
 
   test "start_link" do
     {:ok, pid} = Sequence.start_link([1..4], 5, 1)
diff --git a/apps/indexer/test/indexer_test.exs b/apps/indexer/test/indexer_test.exs
index 040d7adeb7..4badfd1907 100644
--- a/apps/indexer/test/indexer_test.exs
+++ b/apps/indexer/test/indexer_test.exs
@@ -1,8 +1,6 @@
-defmodule Explorer.IndexerTest do
+defmodule IndexerTest do
   use Explorer.DataCase, async: true
 
-  alias Explorer.Indexer
-
   import Explorer.Factory
 
   doctest Indexer
diff --git a/apps/indexer/test/support/indexer/address_balance_fetcher_case.ex b/apps/indexer/test/support/indexer/address_balance_fetcher_case.ex
index 5ec9a18a9f..e1af1430ad 100644
--- a/apps/indexer/test/support/indexer/address_balance_fetcher_case.ex
+++ b/apps/indexer/test/support/indexer/address_balance_fetcher_case.ex
@@ -1,5 +1,5 @@
-defmodule Explorer.Indexer.AddressBalanceFetcherCase do
-  alias Explorer.Indexer.AddressBalanceFetcher
+defmodule Indexer.AddressBalanceFetcherCase do
+  alias Indexer.AddressBalanceFetcher
 
   def start_supervised!(options \\ []) when is_list(options) do
     options
diff --git a/apps/indexer/test/support/indexer/internal_transaction_fetcher_case.ex b/apps/indexer/test/support/indexer/internal_transaction_fetcher_case.ex
index bd514c6116..dd9abb862f 100644
--- a/apps/indexer/test/support/indexer/internal_transaction_fetcher_case.ex
+++ b/apps/indexer/test/support/indexer/internal_transaction_fetcher_case.ex
@@ -1,5 +1,5 @@
-defmodule Explorer.Indexer.InternalTransactionFetcherCase do
-  alias Explorer.Indexer.InternalTransactionFetcher
+defmodule Indexer.InternalTransactionFetcherCase do
+  alias Indexer.InternalTransactionFetcher
 
   def start_supervised!(options \\ []) when is_list(options) do
     options
diff --git a/apps/indexer/test/test_helper.exs b/apps/indexer/test/test_helper.exs
index 869559e709..42f3af3fe4 100644
--- a/apps/indexer/test/test_helper.exs
+++ b/apps/indexer/test/test_helper.exs
@@ -1 +1,20 @@
+# https://github.com/CircleCI-Public/circleci-demo-elixir-phoenix/blob/a89de33a01df67b6773ac90adc74c34367a4a2d6/test/test_helper.exs#L1-L3
+junit_folder = Mix.Project.build_path() <> "/junit/#{Mix.Project.config()[:app]}"
+File.mkdir_p!(junit_folder)
+:ok = Application.put_env(:junit_formatter, :report_dir, junit_folder)
+
+# start all dependencies, but not Indexer itself as we need to unit test the supervision tree without and don't want the
+# genesis task scanning in the background
+Application.load(:indexer)
+
+for application <- Application.spec(:indexer, :applications) do
+  Application.ensure_all_started(application)
+end
+
+# no declared in :applications since it is test-only
+{:ok, _} = Application.ensure_all_started(:ex_machina)
+
+ExUnit.configure(formatters: [JUnitFormatter, ExUnit.CLIFormatter])
 ExUnit.start()
+
+Ecto.Adapters.SQL.Sandbox.mode(Explorer.Repo, :manual)
diff --git a/coveralls.json b/coveralls.json
index 38a52b8eb8..186c305327 100644
--- a/coveralls.json
+++ b/coveralls.json
@@ -1,7 +1,7 @@
 {
   "coverage_options": {
     "treat_no_relevant_lines_as_covered": true,
-    "minimum_coverage": 93.7
+    "minimum_coverage": 94.4
   },
   "terminal_options": {
     "file_column_width": 120
diff --git a/mix.exs b/mix.exs
index ff0723faca..4ad4fa19c2 100644
--- a/mix.exs
+++ b/mix.exs
@@ -28,11 +28,19 @@ defmodule ExplorerUmbrella.Mixfile do
 
   ## Private Functions
 
-  defp aliases(:dev) do
+  defp aliases(env) do
+    [
+      # to match behavior of `mix test` in `apps/indexer`, which needs to not start applications for `indexer` to
+      # prevent its supervision tree from starting, which is undesirable in test
+      test: "test --no-start"
+    ] ++ env_aliases(env)
+  end
+
+  defp env_aliases(:dev) do
     []
   end
 
-  defp aliases(_env) do
+  defp env_aliases(_env) do
     [
       compile: "compile --warnings-as-errors"
     ]