diff --git a/README.md b/README.md
index df4dbd5..8685bf1 100644
--- a/README.md
+++ b/README.md
@@ -32,13 +32,17 @@ This repository contains the server application for the LocalSpend system. See a
 
 The server app. is written in [Perl](https://www.perl.org/).
 
+Admin. portal pages are templated using [HTML::EP](https://metacpan.org/pod/distribution/HTML-EP/lib/HTML/EP.pod).
+
 | Technology  | Description                          | Link                |
 |-------------|--------------------------------------|---------------------|
 | Mojolicious | Perl Web framework	                 | [Link][mojolicious] |
 | PostgreSQL	|	Relational database managment system | [Link][postgresql] |
+| SQLite    	|	Relational database managment system | [Link][sqlite] |
 
 [mojolicious]: https://mojolicious.org/
 [postgresql]: https://www.postgresql.org/
+[sqlite]: https://sqlite.org/index.html
 
 ## Features
 
@@ -122,7 +126,7 @@ Test files are found in the `t/` directory.
 
 ## Code Formatting
 
-TODO
+Run `perlcritic lib/` to format all Perl files with [Perl::Critic](https://metacpan.org/pod/Perl::Critic).
 
 ## Documentation
 
diff --git a/cpanfile b/cpanfile
index 041c680..8c2d742 100644
--- a/cpanfile
+++ b/cpanfile
@@ -28,6 +28,7 @@ requires 'Text::CSV';
 requires 'Try::Tiny';
 requires 'Throwable::Error';
 requires 'Minion';
+requires 'Perl::Critic';
 requires 'WWW::FCM::HTTP';
 
 on 'test' => sub {
diff --git a/lib/Pear/LocalLoop/Controller/Admin/Reports.pm b/lib/Pear/LocalLoop/Controller/Admin/Reports.pm
index aff6bc9..5d0991f 100644
--- a/lib/Pear/LocalLoop/Controller/Admin/Reports.pm
+++ b/lib/Pear/LocalLoop/Controller/Admin/Reports.pm
@@ -73,7 +73,7 @@ sub pg_or_sqlite {
     return \$sqlite_sql;
   } else {
     $c->app->log->warn('Unknown Driver Used');
-    return undef;
+    return;
   }
 }
 
diff --git a/lib/Pear/LocalLoop/Controller/Admin/Transactions.pm b/lib/Pear/LocalLoop/Controller/Admin/Transactions.pm
index 514f326..bf3056b 100644
--- a/lib/Pear/LocalLoop/Controller/Admin/Transactions.pm
+++ b/lib/Pear/LocalLoop/Controller/Admin/Transactions.pm
@@ -113,7 +113,7 @@ sub pg_or_sqlite {
     return \$sqlite_sql;
   } else {
     $c->app->log->warn('Unknown Driver Used');
-    return undef;
+    return;
   }
 }
 
diff --git a/lib/Pear/LocalLoop/Controller/Api/Categories.pm b/lib/Pear/LocalLoop/Controller/Api/Categories.pm
index 0ffeae7..84bd9c1 100644
--- a/lib/Pear/LocalLoop/Controller/Api/Categories.pm
+++ b/lib/Pear/LocalLoop/Controller/Api/Categories.pm
@@ -79,7 +79,7 @@ sub pg_or_sqlite {
     return \$sqlite_sql;
   } else {
     $c->app->log->warn('Unknown Driver Used');
-    return undef;
+    return;
   }
 }
 
diff --git a/lib/Pear/LocalLoop/Controller/Api/Stats.pm b/lib/Pear/LocalLoop/Controller/Api/Stats.pm
index 1b78d8b..d9d127c 100644
--- a/lib/Pear/LocalLoop/Controller/Api/Stats.pm
+++ b/lib/Pear/LocalLoop/Controller/Api/Stats.pm
@@ -505,7 +505,7 @@ sub pg_or_sqlite {
     return \$sqlite_sql;
   } else {
     $c->app->log->warn('Unknown Driver Used');
-    return undef;
+    return;
   }
 }
 
diff --git a/lib/Pear/LocalLoop/Controller/Api/V1/Customer/Graphs.pm b/lib/Pear/LocalLoop/Controller/Api/V1/Customer/Graphs.pm
index f48e52b..2f8e4fc 100644
--- a/lib/Pear/LocalLoop/Controller/Api/V1/Customer/Graphs.pm
+++ b/lib/Pear/LocalLoop/Controller/Api/V1/Customer/Graphs.pm
@@ -160,7 +160,7 @@ sub pg_or_sqlite {
     return \$sqlite_sql;
   } else {
     $c->app->log->warn('Unknown Driver Used');
-    return undef;
+    return;
   }
 }
 
diff --git a/lib/Pear/LocalLoop/Controller/Root.pm b/lib/Pear/LocalLoop/Controller/Root.pm
index ef7b4d3..c2dddba 100644
--- a/lib/Pear/LocalLoop/Controller/Root.pm
+++ b/lib/Pear/LocalLoop/Controller/Root.pm
@@ -16,7 +16,7 @@ sub under {
     return 1;
   }
   $c->redirect_to('/');
-  return undef;
+  return;
 }
 
 sub auth_login {
diff --git a/lib/Pear/LocalLoop/Schema/ResultSet/Leaderboard.pm b/lib/Pear/LocalLoop/Schema/ResultSet/Leaderboard.pm
index a5ba33b..5c94898 100644
--- a/lib/Pear/LocalLoop/Schema/ResultSet/Leaderboard.pm
+++ b/lib/Pear/LocalLoop/Schema/ResultSet/Leaderboard.pm
@@ -13,7 +13,7 @@ sub get_latest {
 
   my $type_result = $self->find_by_type( $type );
 
-  return undef unless defined $type_result;
+  return unless defined $type_result;
 
   my $latest = $type_result->search_related('sets', {}, {
     order_by => { -desc => 'date' },
@@ -29,7 +29,7 @@ sub create_new {
 
   my $type_result = $self->find_by_type($type);
 
-  return undef unless $type_result;
+  return unless $type_result;
 
   return $type_result->create_new($date);
 }
diff --git a/lib/Pear/LocalLoop/Schema/Script/DeploymentHandler.pm b/lib/Pear/LocalLoop/Schema/Script/DeploymentHandler.pm
index a0a789c..9372a9f 100644
--- a/lib/Pear/LocalLoop/Schema/Script/DeploymentHandler.pm
+++ b/lib/Pear/LocalLoop/Schema/Script/DeploymentHandler.pm
@@ -1,5 +1,8 @@
 package Pear::LocalLoop::Schema::Script::DeploymentHandler;
 
+use strict;
+use warnings;
+
 use MooX::Options::Actions;
 use Module::Runtime qw/ use_module /;
 use DBIx::Class::DeploymentHandler;