diff --git a/CHANGELOG.md b/CHANGELOG.md
index 07cf76ff..be4d363b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 * Adjust Admin List Order
 * Add __toString methods to Entities
+* Improve fixture loading while increasing the number of fixtures
 
 # 3.3.1 (2023.11.12)
 
@@ -60,7 +61,7 @@
 
 # 2.7.17 (2021.12.30)
 
-* Set creationTime and updatedTime in all entity constructors (Fixes #207) 
+* Set creationTime and updatedTime in all entity constructors (Fixes #207)
 * Update to symfony 4.3.36
 * Update dependencies
 
@@ -145,8 +146,8 @@
 # 2.7.3 (2020.10.21)
 
 * Improve OpenPGP key import filter:
-  - Keep UIDs with valid email address but without realname
-  - Drop UIDs with invalid email address that have the valid email
+  * Keep UIDs with valid email address but without realname
+  * Drop UIDs with invalid email address that have the valid email
     address in realname
 
 # 2.7.2 (2020.10.21)
diff --git a/codecov.yml b/codecov.yml
new file mode 100644
index 00000000..e900aaee
--- /dev/null
+++ b/codecov.yml
@@ -0,0 +1,9 @@
+---
+ignore:
+  - "config"
+  - "features"
+  - "hugo"
+  - "public"
+  - "src/DataFixtures"
+  - "templates"
+  - "tests"
diff --git a/src/DataFixtures/LoadAliasData.php b/src/DataFixtures/LoadAliasData.php
index 76ac0877..dd8ca804 100644
--- a/src/DataFixtures/LoadAliasData.php
+++ b/src/DataFixtures/LoadAliasData.php
@@ -2,28 +2,14 @@
 
 namespace App\DataFixtures;
 
-use App\Entity\Domain;
 use App\Entity\User;
 use App\Factory\AliasFactory;
-use App\Repository\DomainRepository;
 use Doctrine\Bundle\FixturesBundle\Fixture;
 use Doctrine\Common\DataFixtures\OrderedFixtureInterface;
 use Doctrine\Persistence\ObjectManager;
-use Symfony\Component\DependencyInjection\ContainerAwareInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
 
-class LoadAliasData extends Fixture implements OrderedFixtureInterface, ContainerAwareInterface
+class LoadAliasData extends Fixture implements OrderedFixtureInterface
 {
-    private ContainerInterface $container;
-
-    /**
-     * {@inheritdoc}
-     */
-    public function setContainer(ContainerInterface $container = null): void
-    {
-        $this->container = $container;
-    }
-
     /**
      * {@inheritdoc}
      */
@@ -32,23 +18,25 @@ public function load(ObjectManager $manager): void
         $user = $manager->getRepository(User::class)->findByEmail('admin@example.org');
 
         for ($i = 1; $i < 5; ++$i) {
-            $alias = AliasFactory::create($user, 'alias'.$i);
+            $alias = AliasFactory::create($user, null);
 
             $manager->persist($alias);
-            $manager->flush();
         }
 
-        for ($i = 1; $i < 5; ++$i) {
-            $alias = AliasFactory::create($user, null);
+        $users = $manager->getRepository(User::class)->findAll();
+
+        for ($i = 1; $i < 500; ++$i) {
+            $alias = AliasFactory::create($users[random_int(0, count($users) - 1)], 'alias' . $i);
 
             $manager->persist($alias);
-            $manager->flush();
+
+            if (($i % 100) === 0) {
+                $manager->flush();
+            }
         }
-    }
 
-    private function getRepository(): DomainRepository
-    {
-        return $this->container->get('doctrine')->getRepository(Domain::class);
+        $manager->flush();
+        $manager->clear();
     }
 
     /**
diff --git a/src/DataFixtures/LoadDomainData.php b/src/DataFixtures/LoadDomainData.php
index 149682d4..650832f0 100644
--- a/src/DataFixtures/LoadDomainData.php
+++ b/src/DataFixtures/LoadDomainData.php
@@ -24,8 +24,10 @@ public function load(ObjectManager $manager): void
             $domain->setName($name);
 
             $manager->persist($domain);
-            $manager->flush();
         }
+
+        $manager->flush();
+        $manager->clear();
     }
 
     /**
diff --git a/src/DataFixtures/LoadUserData.php b/src/DataFixtures/LoadUserData.php
index e8d850f9..28d12bb0 100644
--- a/src/DataFixtures/LoadUserData.php
+++ b/src/DataFixtures/LoadUserData.php
@@ -16,6 +16,8 @@ class LoadUserData extends Fixture implements OrderedFixtureInterface, Container
 {
     private const PASSWORD = 'password';
 
+    private string $passwordHash;
+
     private array $users = [
         ['email' => 'admin@example.org', 'roles' => [Roles::ADMIN]],
         ['email' => 'user@example.org', 'roles' => [Roles::USER]],
@@ -41,6 +43,11 @@ public function setContainer(ContainerInterface $container = null): void
      */
     public function load(ObjectManager $manager): void
     {
+        $user = new User();
+        $user->setPlainPassword(self::PASSWORD);
+        $this->getPasswordUpdater()->updatePassword($user);
+        $this->passwordHash = $user->getPassword();
+
         $this->loadStaticUsers($manager);
         $this->loadRandomUsers($manager);
     }
@@ -58,20 +65,13 @@ private function getPasswordUpdater(): PasswordUpdater
         return $this->container->get(PasswordUpdater::class);
     }
 
-    /**
-     * @param $domain
-     * @param $email
-     * @param $roles
-     */
-    private function buildUser($domain, $email, $roles): User
+    private function buildUser(Domain $domain, string $email, array $roles): User
     {
         $user = new User();
         $user->setDomain($domain);
         $user->setEmail($email);
         $user->setRoles($roles);
-        $user->setPlainPassword(self::PASSWORD);
-
-        $this->getPasswordUpdater()->updatePassword($user);
+        $user->setPassword($this->passwordHash);
 
         return $user;
     }
@@ -89,8 +89,10 @@ private function loadStaticUsers(ObjectManager $manager): void
             $user = $this->buildUser($domain, $email, $roles);
 
             $manager->persist($user);
-            $manager->flush();
         }
+
+        $manager->flush();
+        $manager->clear();
     }
 
     /**
@@ -99,12 +101,11 @@ private function loadStaticUsers(ObjectManager $manager): void
     private function loadRandomUsers(ObjectManager $manager): void
     {
         $domainRepository = $manager->getRepository(Domain::class);
+        $domain = $domainRepository->findOneBy(['name' => 'example.org']);
+        $roles = [Roles::USER];
 
-        for ($i = 0; $i < 500; ++$i) {
-            $email = sprintf('%s@example.org', uniqid('', true));
-            $splitted = explode('@', $email);
-            $roles = [Roles::USER];
-            $domain = $domainRepository->findOneBy(['name' => $splitted[1]]);
+        for ($i = 0; $i < 15000; ++$i) {
+            $email = sprintf('user-%d@%s', $i, $domain->getName());
 
             $user = $this->buildUser($domain, $email, $roles);
             $user->setCreationTime(new \DateTime(sprintf('-%s days', random_int(1, 25))));
@@ -118,7 +119,13 @@ private function loadRandomUsers(ObjectManager $manager): void
             }
 
             $manager->persist($user);
-            $manager->flush();
+
+            if (($i % 100) === 0) {
+                $manager->flush();
+            }
         }
+
+        $manager->flush();
+        $manager->clear();
     }
 }
diff --git a/src/DataFixtures/LoadVoucherData.php b/src/DataFixtures/LoadVoucherData.php
index 92fccac9..b3264e50 100644
--- a/src/DataFixtures/LoadVoucherData.php
+++ b/src/DataFixtures/LoadVoucherData.php
@@ -3,26 +3,13 @@
 namespace App\DataFixtures;
 
 use App\Entity\User;
-use App\Entity\Voucher;
 use App\Factory\VoucherFactory;
 use Doctrine\Bundle\FixturesBundle\Fixture;
 use Doctrine\Common\DataFixtures\OrderedFixtureInterface;
 use Doctrine\Persistence\ObjectManager;
-use Symfony\Component\DependencyInjection\ContainerAwareInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
 
-class LoadVoucherData extends Fixture implements OrderedFixtureInterface, ContainerAwareInterface
+class LoadVoucherData extends Fixture implements OrderedFixtureInterface
 {
-    private ContainerInterface $container;
-
-    /**
-     * {@inheritdoc}
-     */
-    public function setContainer(ContainerInterface $container = null): void
-    {
-        $this->container = $container;
-    }
-
     /**
      * {@inheritdoc}
      *
@@ -46,6 +33,10 @@ public function load(ObjectManager $manager): void
             }
 
             $manager->persist($voucher);
+
+            if (($i % 100) === 0) {
+                $manager->flush();
+            }
         }
 
         // add redeemed voucher to a suspicious parent
@@ -58,6 +49,7 @@ public function load(ObjectManager $manager): void
         $manager->persist($voucher);
 
         $manager->flush();
+        $manager->clear();
     }
 
     /**