diff --git a/.gitignore b/.gitignore
index 5b407a0..68b52d3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,3 +23,5 @@
 !/web/*/custom/**
 
 !/_lessons/**
+!/phpstan.neon
+!/tests/**
diff --git a/build.yaml b/build.yaml
index 23ef6c0..032fa9f 100644
--- a/build.yaml
+++ b/build.yaml
@@ -11,6 +11,8 @@ flake:
 git:
   ignore:
     - '!/_lessons/**'
+    - '!/phpstan.neon'
+    - '!/tests/**'
 
 experimental:
   createTmuxStartupFile: true
diff --git a/composer.json b/composer.json
index ff80648..d51cbaf 100644
--- a/composer.json
+++ b/composer.json
@@ -98,6 +98,12 @@
         "brianium/paratest": "^6.11",
         "dealerdirect/phpcodesniffer-composer-installer": "^1.0",
         "drupal/coder": "^8.3",
-        "drupal/core-dev": "^10.2"
+        "drupal/core-dev": "^10.2",
+        "phpat/phpat": "^0.10.13"
+    },
+    "autoload": {
+        "psr-4": {
+            "Tests\\Architecture\\": "tests/Architecture"
+        }
     }
 }
diff --git a/composer.lock b/composer.lock
index 922abde..6f00ac5 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "bb0170d2be16b500e494326ee69377a3",
+    "content-hash": "50098baf2c6068540532ef1fe95aa155",
     "packages": [
         {
             "name": "asm89/stack-cors",
@@ -8594,6 +8594,63 @@
             },
             "time": "2023-11-08T12:57:08+00:00"
         },
+        {
+            "name": "phpat/phpat",
+            "version": "0.10.13",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/carlosas/phpat.git",
+                "reference": "4954eebf9b456837720b07486d29828461ed24fc"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/carlosas/phpat/zipball/4954eebf9b456837720b07486d29828461ed24fc",
+                "reference": "4954eebf9b456837720b07486d29828461ed24fc",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.4 || ^8.0",
+                "phpstan/phpstan": "^1.3"
+            },
+            "require-dev": {
+                "friendsofphp/php-cs-fixer": "^3.0",
+                "kubawerlos/php-cs-fixer-custom-fixers": "^3.16",
+                "phpunit/phpunit": "^9.0",
+                "vimeo/psalm": "^4.0 || ^5.0"
+            },
+            "type": "phpstan-extension",
+            "extra": {
+                "phpstan": {
+                    "includes": [
+                        "extension.neon"
+                    ]
+                }
+            },
+            "autoload": {
+                "files": [
+                    "helpers.php"
+                ],
+                "psr-4": {
+                    "PHPat\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Carlos Alandete Sastre",
+                    "email": "carlos.alandete@gmail.com"
+                }
+            ],
+            "description": "PHP Architecture Tester",
+            "support": {
+                "issues": "https://github.com/carlosas/phpat/issues",
+                "source": "https://github.com/carlosas/phpat/tree/0.10.13"
+            },
+            "time": "2024-01-04T17:18:43+00:00"
+        },
         {
             "name": "phpdocumentor/reflection-common",
             "version": "2.2.0",
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..379a188
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,10 @@
+parameters:
+  level: 5
+  paths:
+    - web/modules/custom
+
+services:
+  -
+    class: Tests\Architecture\ArchTest
+    tags:
+      - phpat.test
diff --git a/tests/Architecture/ArchTest.php b/tests/Architecture/ArchTest.php
new file mode 100644
index 0000000..cfdd9d2
--- /dev/null
+++ b/tests/Architecture/ArchTest.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Tests\Architecture;
+
+use Drupal\Core\Controller\ControllerBase;
+use PHPat\Selector\Selector;
+use PHPat\Test\Builder\Rule;
+use PHPat\Test\PHPat;
+
+final class ArchTest {
+
+  public function test_classes_should_be_final(): Rule {
+    return PHPat::rule()
+      ->classes(Selector::inNamespace('Drupal\atdc'))
+      ->shouldBeFinal();
+  }
+
+  public function test_controllers_should_extend_ControllerBase(): Rule {
+    return PHPat::rule()
+      ->classes(Selector::inNamespace('Drupal\atdc\Controller'))
+      ->shouldExtend()
+      ->classes(Selector::classname(ControllerBase::class));
+  }
+
+  public function test_controllers_should_have_the_Controller_suffix(): Rule {
+    return PHPat::rule()
+      ->classes(Selector::inNamespace('Drupal\atdc\Controller'))
+      ->shouldBeNamed(
+        classname: '/Controller$/',
+        regex: TRUE,
+      );
+  }
+
+}
diff --git a/web/modules/custom/atdc/src/Controller/BlogPageController.php b/web/modules/custom/atdc/src/Controller/BlogPageController.php
index fb1e3fe..1d4978d 100644
--- a/web/modules/custom/atdc/src/Controller/BlogPageController.php
+++ b/web/modules/custom/atdc/src/Controller/BlogPageController.php
@@ -6,7 +6,7 @@ use Drupal\atdc\Repository\PostNodeRepository;
 use Drupal\Core\Controller\ControllerBase;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
-class BlogPageController extends ControllerBase {
+final class BlogPageController extends ControllerBase {
 
   public function __construct(
     private PostNodeRepository $postNodeRepository,