diff --git a/.php-cs-fixer.dist.php b/.php-cs-fixer.dist.php
index 4199fa7..c5631c0 100644
--- a/.php-cs-fixer.dist.php
+++ b/.php-cs-fixer.dist.php
@@ -2,8 +2,11 @@
 
 declare(strict_types=1);
 
-$finder = PhpCsFixer\Finder::create()
-    ->in(['src', 'tests'])
+$finder = (new PhpCsFixer\Finder())
+    ->in(__DIR__)
+    ->exclude([
+        'node_modules',
+    ])
 ;
 
 $config = new PhpCsFixer\Config();
diff --git a/README.md b/README.md
index 9165bf9..f41e824 100644
--- a/README.md
+++ b/README.md
@@ -199,14 +199,17 @@ _Note: Don't set the schedule frequency to high to not overload their website_
 
 ## Run (serverless)
 
-Termin can also be run as a serverless application. Configure the application like you would normally.
+Termin can also be run as a serverless application. Configure the application like you would like any other way.
 
-Then configure your environment with [serverless tooling][9].
+Install serverless toolchain:
 
 ```bash
 npm install
 ```
 
+Then configure your environment with [serverless tooling][9].
+
+
 And finally deploy:
 
 ```bash
diff --git a/app.php b/app.php
index 500438a..5e1e664 100644
--- a/app.php
+++ b/app.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use Inverse\Termin\Config\ConfigParser;
 use Inverse\Termin\Container;
 use Symfony\Component\Yaml\Yaml;
@@ -7,7 +9,7 @@
 require __DIR__.'/vendor/autoload.php';
 
 $configLoader = new ConfigParser();
-$config = $configLoader->parse(Yaml::parseFile(__DIR__ . '/config.yml'));
+$config = $configLoader->parse(Yaml::parseFile(__DIR__.'/config.yml'));
 
 $container = new Container($config);
 
diff --git a/index.php b/index.php
deleted file mode 100644
index 346496c..0000000
--- a/index.php
+++ /dev/null
@@ -1,7 +0,0 @@
-<?php declare(strict_types=1);
-
-require __DIR__ . '/vendor/autoload.php';
-
-return function ($event) {
-    return 'Hello ' . ($event['name'] ?? 'world');
-};
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index f4db291..ab89a96 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -4,5 +4,5 @@ parameters:
 		- %currentWorkingDirectory%/tests
 	excludePaths:
 		- %currentWorkingDirectory%/src/Container.php
-	level: 7
+	level: 8
 	checkMissingIterableValueType: false
diff --git a/serverless.php b/serverless.php
index 6c3abd6..68eca36 100644
--- a/serverless.php
+++ b/serverless.php
@@ -1,5 +1,7 @@
 <?php
- 
+
+declare(strict_types=1);
+
 use Bref\Context\Context;
 use Inverse\Termin\Config\ConfigParser;
 use Inverse\Termin\Container;
@@ -7,21 +9,20 @@
 
 require __DIR__.'/vendor/autoload.php';
 
-
-class Handler implements \Bref\Event\Handler
+class Handler implements Bref\Event\Handler
 {
     public function handle($event, Context $context)
     {
         $configLoader = new ConfigParser();
-        $config = $configLoader->parse(Yaml::parseFile(__DIR__ . '/config.yml'));
-        
+        $config = $configLoader->parse(Yaml::parseFile(__DIR__.'/config.yml'));
+
         $container = new Container($config, 'serverless');
-        
+
         $termin = $container->getTermin();
         $termin->run($config->getSites());
-        
+
         return 'OK';
     }
 }
- 
+
 return new Handler();
diff --git a/tests/Config/ConfigParserTest.php b/tests/Config/ConfigParserTest.php
index 34312e3..1a0e3c8 100644
--- a/tests/Config/ConfigParserTest.php
+++ b/tests/Config/ConfigParserTest.php
@@ -89,7 +89,7 @@ public function testParseValid(): void
         $config = $this->configParser->parse($this->getBasicConfig());
 
         self::assertCount(1, $config->getSites());
-        self::assertEquals($config->getSites()[0]->getLabel(), 'Important');
+        self::assertEquals('Important', $config->getSites()[0]->getLabel());
         self::assertEquals(['param_1' => 'value_1'], $config->getSites()[0]->getParams());
         self::assertFalse($config->isAllowMultipleNotifications());
         self::assertNull($config->getTelegram());
@@ -120,8 +120,13 @@ public function testParseNtfyValidDefaultServer(): void
             ],
         ]);
 
-        self::assertEquals($config->getNtfy()->getServer(), Ntfy::DEFAULT_SERVER);
-        self::assertEquals($config->getNtfy()->getTopic(), 'termin_fun');
+        $ntfy = $config->getNtfy();
+        if (null === $ntfy) {
+            self::fail('Ntfy config must not be null');
+        }
+
+        self::assertEquals(Ntfy::DEFAULT_SERVER, $ntfy->getServer());
+        self::assertEquals('termin_fun', $ntfy->getTopic());
     }
 
     public function testParseNtfyValid(): void
@@ -133,8 +138,13 @@ public function testParseNtfyValid(): void
             ],
         ]);
 
-        self::assertEquals($config->getNtfy()->getServer(), 'https://my-server.com');
-        self::assertEquals($config->getNtfy()->getTopic(), 'termin_fun');
+        $ntfy = $config->getNtfy();
+        if (null === $ntfy) {
+            self::fail('Ntfy config must not be null');
+        }
+
+        self::assertEquals('https://my-server.com', $ntfy->getServer());
+        self::assertEquals('termin_fun', $ntfy->getTopic());
     }
 
     public function testParseTelegramEmpty(): void
@@ -202,8 +212,13 @@ public function testParseTelegramValid(): void
             ],
         ]);
 
-        self::assertEquals($config->getTelegram()->getApiKey(), 'api');
-        self::assertEquals($config->getTelegram()->getChatId(), 1);
+        $telegram = $config->getTelegram();
+        if (null === $telegram) {
+            self::fail('Telegram config must not be null');
+        }
+
+        self::assertEquals('api', $telegram->getApiKey());
+        self::assertEquals(1, $telegram->getChatId());
     }
 
     public function testParsePushbulletEmpty(): void
@@ -235,7 +250,12 @@ public function testParsePushbulletValid(): void
             ],
         ]);
 
-        self::assertEquals($config->getPushbullet()->getApiToken(), 'token');
+        $pushbullet = $config->getPushbullet();
+        if (null === $pushbullet) {
+            self::fail('Pushbullet config must not be null');
+        }
+
+        self::assertEquals('token', $pushbullet->getApiToken());
     }
 
     public function testParseRulesNotArray(): void