diff --git a/core/drupalci.yml b/core/drupalci.yml
index 94aa2ad22f..9bd5313103 100644
--- a/core/drupalci.yml
+++ b/core/drupalci.yml
@@ -4,43 +4,8 @@
 build:
   assessment:
     testing:
-      # Run code quality checks.
-      container_command.commit-checks:
-        commands:
-          - "core/scripts/dev/commit-code-check.sh --drupalci"
-        halt-on-fail: true
-      # run_tests task is executed several times in order of performance speeds.
-      # halt-on-fail can be set on the run_tests tasks in order to fail fast.
-      # suppress-deprecations is false in order to be alerted to usages of
-      # deprecated code.
-      run_tests.phpunit:
-        types: 'PHPUnit-Unit'
-        testgroups: '--all'
-        suppress-deprecations: false
-        halt-on-fail: false
-      run_tests.kernel:
-        types: 'PHPUnit-Kernel'
-        testgroups: '--all'
-        suppress-deprecations: false
-        halt-on-fail: false
-      run_tests.build:
-        # Limit concurrency due to disk space concerns.
-        concurrency: 15
-        types: 'PHPUnit-Build'
-        testgroups: '--all'
-        suppress-deprecations: false
-        halt-on-fail: false
       run_tests.functional:
         types: 'PHPUnit-Functional'
-        testgroups: '--all'
-        suppress-deprecations: false
-        halt-on-fail: false
-      run_tests.javascript:
-        concurrency: 15
-        types: 'PHPUnit-FunctionalJavascript'
-        testgroups: '--all'
+        testgroups: '--class "\Drupal\Tests\system\Functional\UpdateSystem\UpdatePathTestBaseFilledTest"'
         suppress-deprecations: false
         halt-on-fail: false
-      # Run nightwatch testing.
-      # @see https://www.drupal.org/project/drupal/issues/2869825
-      nightwatchjs: {}
diff --git a/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php b/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php
index 29ed1541dd..3204dd0834 100644
--- a/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php
+++ b/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php
@@ -156,10 +156,10 @@ protected function assertOffCanvasBlockFormIsValid() {
    * {@inheritdoc}
    */
   protected function getTestThemes() {
-    // Remove 'seven' theme. Settings Tray "Edit Mode" will not work with
-    // 'seven' because it removes all contextual links.
+    // Remove 'claro' theme. Settings Tray "Edit Mode" will not work with this
+    // theme because it removes all contextual links.
     return array_filter(parent::getTestThemes(), function ($theme) {
-      return $theme !== 'seven';
+      return ($theme !== 'claro');
     });
   }
 
diff --git a/core/modules/system/tests/modules/image_lazy_load_test/src/Controller/ImageLazyLoadController.php b/core/modules/system/tests/modules/image_lazy_load_test/src/Controller/ImageLazyLoadController.php
index 39a3f2cb65..3877ad1c8f 100644
--- a/core/modules/system/tests/modules/image_lazy_load_test/src/Controller/ImageLazyLoadController.php
+++ b/core/modules/system/tests/modules/image_lazy_load_test/src/Controller/ImageLazyLoadController.php
@@ -18,7 +18,7 @@ class ImageLazyLoadController extends ControllerBase {
   public function renderImage() {
     $images['with-dimensions'] = [
       '#theme' => 'image',
-      '#uri' => '/core/themes/bartik/logo.svg',
+      '#uri' => '/core/themes/olivero/logo.svg',
       '#alt' => 'Image lazy load testing image',
       '#prefix' => '<div id="with-dimensions">',
       '#suffix' => '</div>',
@@ -28,7 +28,7 @@ public function renderImage() {
 
     $images['without-dimensions'] = [
       '#theme' => 'image',
-      '#uri' => '/core/themes/bartik/logo.svg',
+      '#uri' => '/core/themes/olivero/logo.svg',
       '#alt' => 'Image lazy load testing image without dimensions',
       '#prefix' => '<div id="without-dimensions">',
       '#suffix' => '</div>',
@@ -36,7 +36,7 @@ public function renderImage() {
 
     $images['override-loading-attribute'] = [
       '#theme' => 'image',
-      '#uri' => '/core/themes/bartik/logo.svg',
+      '#uri' => '/core/themes/olivero/logo.svg',
       '#alt' => 'Image lazy load test loading attribute can be overridden',
       '#prefix' => '<div id="override-loading-attribute">',
       '#suffix' => '</div>',
diff --git a/core/modules/system/tests/src/Functional/System/ThemeTest.php b/core/modules/system/tests/src/Functional/System/ThemeTest.php
index 87d9259c5f..19574c4d9e 100644
--- a/core/modules/system/tests/src/Functional/System/ThemeTest.php
+++ b/core/modules/system/tests/src/Functional/System/ThemeTest.php
@@ -286,11 +286,11 @@ public function testThemeSettingsRenderCacheClear() {
    * Tests the administration theme functionality.
    */
   public function testAdministrationTheme() {
-    $this->container->get('theme_installer')->install(['seven']);
+    $this->container->get('theme_installer')->install(['claro']);
 
     // Install an administration theme and show it on the node admin pages.
     $edit = [
-      'admin_theme' => 'seven',
+      'admin_theme' => 'claro',
       'use_admin_theme' => TRUE,
     ];
     $this->drupalGet('admin/appearance');
@@ -307,7 +307,7 @@ public function testAdministrationTheme() {
 
     // Check that the administration theme is used on an administration page.
     $this->drupalGet('admin/config');
-    $this->assertSession()->responseContains('core/themes/seven');
+    $this->assertSession()->responseContains('core/themes/claro');
 
     // Check that the site default theme used on node page.
     $this->drupalGet('node/' . $this->node->id());
@@ -315,11 +315,11 @@ public function testAdministrationTheme() {
 
     // Check that the administration theme is used on the add content page.
     $this->drupalGet('node/add');
-    $this->assertSession()->responseContains('core/themes/seven');
+    $this->assertSession()->responseContains('core/themes/claro');
 
     // Check that the administration theme is used on the edit content page.
     $this->drupalGet('node/' . $this->node->id() . '/edit');
-    $this->assertSession()->responseContains('core/themes/seven');
+    $this->assertSession()->responseContains('core/themes/claro');
 
     // Disable the admin theme on the node admin pages.
     $edit = [
@@ -334,7 +334,7 @@ public function testAdministrationTheme() {
 
     // Check that the administration theme is used on an administration page.
     $this->drupalGet('admin/config');
-    $this->assertSession()->responseContains('core/themes/seven');
+    $this->assertSession()->responseContains('core/themes/claro');
 
     // Ensure that the admin theme is also visible on the 403 page.
     $normal_user = $this->drupalCreateUser(['view the administration theme']);
@@ -342,7 +342,7 @@ public function testAdministrationTheme() {
     // Check that the administration theme is used on an administration page.
     $this->drupalGet('admin/config');
     $this->assertSession()->statusCodeEquals(403);
-    $this->assertSession()->responseContains('core/themes/seven');
+    $this->assertSession()->responseContains('core/themes/claro');
     $this->drupalLogin($this->adminUser);
 
     // Check that the site default theme used on the add content page.
@@ -421,25 +421,24 @@ public function testInvalidTheme() {
    * Tests uninstalling of themes works.
    */
   public function testUninstallingThemes() {
-    // Install Olivero and set it as the default theme.
+    // Install olivero.
     \Drupal::service('theme_installer')->install(['olivero']);
-    // Set up seven as the admin theme.
-    \Drupal::service('theme_installer')->install(['seven']);
+    // Set up claro as the admin theme.
+    \Drupal::service('theme_installer')->install(['claro']);
     $edit = [
-      'admin_theme' => 'seven',
+      'admin_theme' => 'claro',
       'use_admin_theme' => TRUE,
     ];
     $this->drupalGet('admin/appearance');
     $this->submitForm($edit, 'Save configuration');
-    $this->drupalGet('admin/appearance');
-    $this->clickLink('Set as default');
-
-    // Check that seven cannot be uninstalled as it is the admin theme.
-    $this->assertSession()->responseNotContains('Uninstall Seven theme');
+    // Set olivero as the default theme.
+    $this->cssSelect('a[title="Set Olivero as default theme"]')[0]->click();
+    // Check that claro cannot be uninstalled as it is the admin theme.
+    $this->assertSession()->responseNotContains('Uninstall claro theme');
     // Check that olivero cannot be uninstalled as it is the default theme.
     $this->assertSession()->responseNotContains('Uninstall Olivero theme');
     // Check that the classy theme cannot be uninstalled as it is a base theme
-    // of seven and olivero.
+    // of claro and olivero.
     $this->assertSession()->responseNotContains('Uninstall Classy theme');
 
     // Install Stark and set it as the default theme.
@@ -452,8 +451,8 @@ public function testUninstallingThemes() {
     $this->drupalGet('admin/appearance');
     $this->submitForm($edit, 'Save configuration');
 
-    // Check that seven can be uninstalled now.
-    $this->assertSession()->responseContains('Uninstall Seven theme');
+    // Check that claro can be uninstalled now.
+    $this->assertSession()->responseContains('Uninstall claro theme');
     // Check that the classy theme still cannot be uninstalled as it is a
     // base theme of olivero.
     $this->assertSession()->responseNotContains('Uninstall Classy theme');
@@ -468,12 +467,11 @@ public function testUninstallingThemes() {
     // base themes have been.
     $this->assertSession()->responseNotContains('Uninstall Classy theme');
 
-    // Uninstall each of the three themes starting with Olivero.
-    $this->clickLink('Uninstall');
+    // Uninstall each of the two themes starting with Olivero.
+    $this->cssSelect('a[title="Uninstall Olivero theme"]')[0]->click();
     $this->assertSession()->responseContains('The <em class="placeholder">Olivero</em> theme has been uninstalled');
-    // Seven is the second in the list.
-    $this->clickLink('Uninstall');
-    $this->assertSession()->responseContains('The <em class="placeholder">Seven</em> theme has been uninstalled');
+    $this->cssSelect('a[title="Uninstall Claro theme"]')[0]->click();
+    $this->assertSession()->responseContains('The <em class="placeholder">Claro</em> theme has been uninstalled');
 
     // Check that the classy theme still can't be uninstalled as it is hidden.
     $this->assertSession()->responseNotContains('Uninstall Classy theme');
diff --git a/core/modules/system/tests/src/Functional/Theme/ThemeTokenTest.php b/core/modules/system/tests/src/Functional/Theme/ThemeTokenTest.php
index 44308f4f79..620cba5b25 100644
--- a/core/modules/system/tests/src/Functional/Theme/ThemeTokenTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/ThemeTokenTest.php
@@ -46,11 +46,11 @@ public function testThemeToken() {
     $settings = $this->getDrupalSettings();
     $this->assertNull($settings['ajaxPageState']['theme_token']);
 
-    // Install 'seven' and configure it as administrative theme.
-    $this->container->get('theme_installer')->install(['seven']);
-    $this->config('system.theme')->set('admin', 'seven')->save();
+    // Install 'claro' and configure it as administrative theme.
+    $this->container->get('theme_installer')->install(['claro']);
+    $this->config('system.theme')->set('admin', 'claro')->save();
 
-    // Revisit the page. This time the page is displayed using the 'seven' theme
+    // Revisit the page. This time the page is displayed using the 'claro' theme
     // and that is different from the default theme ('classy').
     $this->drupalGet('admin/structure/block');
     $settings = $this->getDrupalSettings();
diff --git a/core/modules/system/tests/src/Functional/UpdateSystem/BrokenCacheUpdateTest.php b/core/modules/system/tests/src/Functional/UpdateSystem/BrokenCacheUpdateTest.php
index 2250b1ba9e..23c864d44a 100644
--- a/core/modules/system/tests/src/Functional/UpdateSystem/BrokenCacheUpdateTest.php
+++ b/core/modules/system/tests/src/Functional/UpdateSystem/BrokenCacheUpdateTest.php
@@ -46,7 +46,7 @@ public function testUpdate() {
       'checksum' => 0,
     ];
     $insert->fields($fields);
-    $fields['cid'] = 'element_info_build:seven';
+    $fields['cid'] = 'element_info_build:claro';
     $fields['tags'] = 'element_info_build';
     $insert->values(array_values($fields));
     $fields['cid'] = 'element_info_build:stark';
@@ -56,7 +56,7 @@ public function testUpdate() {
     $this->runUpdates();
     // Caches should have been cleared at this point.
     $count = (int) $connection->select('cache_discovery')
-      ->condition('cid', ['element_info', 'element_info_build:seven', 'element_info_build:stark'], 'IN')
+      ->condition('cid', ['element_info', 'element_info_build:claro', 'element_info_build:stark'], 'IN')
       ->countQuery()
       ->execute()
       ->fetchField();
diff --git a/core/modules/system/tests/src/Functional/UpdateSystem/UpdatePathTestBaseFilledTest.php b/core/modules/system/tests/src/Functional/UpdateSystem/UpdatePathTestBaseFilledTest.php
index 8088063f7e..9419e9492e 100644
--- a/core/modules/system/tests/src/Functional/UpdateSystem/UpdatePathTestBaseFilledTest.php
+++ b/core/modules/system/tests/src/Functional/UpdateSystem/UpdatePathTestBaseFilledTest.php
@@ -404,8 +404,8 @@ public function testUpdatedSite() {
 
     // Make sure our themes are still enabled.
     $expected_enabled_themes = [
-      'bartik',
-      'seven',
+      'olivero',
+      'claro',
       'stark',
     ];
     foreach ($expected_enabled_themes as $theme) {
diff --git a/core/modules/system/tests/src/FunctionalJavascript/OffCanvasTestBase.php b/core/modules/system/tests/src/FunctionalJavascript/OffCanvasTestBase.php
index c6596e496d..352dd45423 100644
--- a/core/modules/system/tests/src/FunctionalJavascript/OffCanvasTestBase.php
+++ b/core/modules/system/tests/src/FunctionalJavascript/OffCanvasTestBase.php
@@ -110,7 +110,7 @@ protected function getOffCanvasDialog() {
    *   Theme names to test.
    */
   protected function getTestThemes() {
-    return ['bartik', 'classy', 'olivero', 'seven', 'stable', 'stark'];
+    return ['claro', 'classy', 'olivero', 'stable', 'stark'];
   }
 
   /**
diff --git a/core/modules/system/tests/src/Kernel/Plugin/migrate/source/d7/ThemeSettingsTest.php b/core/modules/system/tests/src/Kernel/Plugin/migrate/source/d7/ThemeSettingsTest.php
index 482e4ddf68..8aa69be39d 100644
--- a/core/modules/system/tests/src/Kernel/Plugin/migrate/source/d7/ThemeSettingsTest.php
+++ b/core/modules/system/tests/src/Kernel/Plugin/migrate/source/d7/ThemeSettingsTest.php
@@ -46,7 +46,7 @@ public function providerSource() {
 
     $tests[0]['source_data']['variable'] = [
       [
-        'name' => 'theme_bartik_settings',
+        'name' => 'theme_olivero_settings',
         'value' => serialize($value),
       ],
     ];
@@ -54,7 +54,7 @@ public function providerSource() {
     // The expected results are nearly identical to the source data.
     $tests[0]['expected_data'] = [
       [
-        'name' => 'theme_bartik_settings',
+        'name' => 'theme_olivero_settings',
         'value' => $value,
       ],
     ];
