diff --git a/app/src/Bootstrap.php b/app/src/Bootstrap.php
index a0903c0..728ec4c 100644
--- a/app/src/Bootstrap.php
+++ b/app/src/Bootstrap.php
@@ -109,7 +109,9 @@ class Bootstrap
 
     /**
      * Taking an instantiated application, sets up all the middleware required
-     * for the application to run.
+     * for the application to run. This appends Middleware in a Global sense,
+     * not per-route. Per-route middleware will be set in the `establishRoutes`
+     * method.
      *
      * @param App $app
      */
diff --git a/app/src/Controller/User/RegisterUserAction.php b/app/src/Controller/User/RegisterUserAction.php
index c5a445f..947bbe6 100644
--- a/app/src/Controller/User/RegisterUserAction.php
+++ b/app/src/Controller/User/RegisterUserAction.php
@@ -17,25 +17,16 @@ class RegisterUserAction extends Controller
 
     public function respond(): Response
     {
-        // get user Data
         $requestData = $this->request->getParsedBody();
-
-        if ($requestData['password'] !== $requestData['checked_password']) {
-            $this->session->getFlash()
-                          ->add('error', "Passwords do not match.");
-            $response = $this->render('user/register.twig');
-            return $response->withStatus(400);
-        }
-
         $user = User::fromArray([
             'email' => $requestData['email'],
             'name' => $requestData['name'],
             'password' => $requestData['password'],
         ]);
 
-        $result = $this->userRepository->save($user);
+        $success = $this->userRepository->save($user);
 
-        if ($result) {
+        if ($success) {
             return $this->render('user/success.twig');
         } else {
             $this->session
@@ -43,6 +34,5 @@ class RegisterUserAction extends Controller
                  ->add('error', "Unable to register user.");
             return $this->render('user/register.twig')->withStatus(400);
         }
-        
     }
 }
diff --git a/app/src/Infrastructure/Middleware.php b/app/src/Infrastructure/Middleware.php
new file mode 100644
index 0000000..8447b69
--- /dev/null
+++ b/app/src/Infrastructure/Middleware.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace Slovocast\Infrastructure;
+
+use Psr\Http\Message\ServerRequestInterface as Request;
+use Psr\Http\Message\ResponseInterface as Response;
+
+abstract class Middleware
+{
+    /**
+     * @param Request $request
+     * @param Response $response
+     * @param callable $next
+     * @return Response
+     */
+    public function __invoke(
+        Request $request, 
+        Response $response, 
+        callable $next
+    ): Response {
+        return $this->invoke($request, $response, $next);
+    }
+
+    /**
+     * To write Middleware, we need to implement this concrete method, and set
+     * the child class as the Middleware in the Application bootstrapping.
+     *
+     * @param Request $request
+     * @param Response $response
+     * @param callable $next
+     * @return Response
+     */
+    abstract public function invoke(
+        Request $request,
+        Response $response,
+        callable $next
+    ): Response;
+}
diff --git a/app/src/Infrastructure/Middleware/VerifyPasswordMiddleware.php b/app/src/Infrastructure/Middleware/VerifyPasswordMiddleware.php
new file mode 100644
index 0000000..78d3b59
--- /dev/null
+++ b/app/src/Infrastructure/Middleware/VerifyPasswordMiddleware.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace Slovocast\Infrastructure\Middleware;
+
+use Slovocast\Infrastructure\Middleware;
+use Psr\Http\Message\ServerRequestInterface as Request;
+use Psr\Http\Message\ResponseInterface as Response;
+
+
+class VerifyPasswordMiddleware extends Middleware
+{
+    public function invoke(
+        Request $request,
+        Response $response,
+        callable $next
+    ): Response {
+        // get user Data
+        $requestData = $request->getParsedBody();
+
+        if ($requestData['password'] !== $requestData['checked_password']) {
+            $this->session->getFlash()
+                          ->add('error', "Passwords do not match.");
+            return $response->withStatus(400);
+        }
+
+        return $response;
+    }
+}
diff --git a/app/src/Routes.php b/app/src/Routes.php
index 7cda3f5..ab3a6fd 100644
--- a/app/src/Routes.php
+++ b/app/src/Routes.php
@@ -8,6 +8,7 @@ use Slovocast\Controller\User\{
     RegisterUserPage,
     RegisterUserAction
 };
+use Slovocast\Infrastructure\Middleware\VerifyPasswordMiddleware;
 
 class Routes
 {
@@ -21,6 +22,7 @@ class Routes
     protected static function users(App $app): void
     {
         $app->get('/users/register', RegisterUserPage::class);
-        $app->post('/users/register', RegisterUserAction::class);
+        $app->post('/users/register', RegisterUserAction::class)
+            ->add(new VerifyPasswordMiddleware());
     }
 }