--- a/Classes/Routing/PageSlugCandidateProvider.php	2023-04-13 09:40:15
+++ b/Classes/Routing/PageSlugCandidateProvider.php	2023-04-13 10:03:15
@@ -18,6 +18,7 @@
 namespace TYPO3\CMS\Core\Routing;

 use Doctrine\DBAL\Connection;
+use TYPO3\CMS\Core\Cache\CacheManager;
 use TYPO3\CMS\Core\Context\Context;
 use TYPO3\CMS\Core\Database\ConnectionPool;
 use TYPO3\CMS\Core\Database\Query\Restriction\DeletedRestriction;
@@ -197,6 +198,19 @@
             $languages = [$languageId];
         }
         $searchLiveRecordsOnly = $this->context->getPropertyFromAspect('workspace', 'isLive');
+        $cache = GeneralUtility::makeInstance(CacheManager::class)->getCache('simple_api');
+        $cacheIdentifier = __FUNCTION__ . '-' . sha1(json_encode([
+            $this->site->getIdentifier(),
+            $searchLiveRecordsOnly,
+            $slugCandidates,
+            $languageId,
+            $excludeUids,
+            $languages
+        ]));
+        $pages = $cache->get($cacheIdentifier);
+        if ($pages !== false) {
+            return $pages;
+        }
         $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)
             ->getQueryBuilderForTable('pages');
         $queryBuilder
@@ -330,6 +344,13 @@
                 }
             }
         }
+        $cacheKeys = array_map(
+            function (int $uid) {
+                return 'pages%' . $uid;
+            },
+            array_column($pages, 'uid')
+        );
+        $cache->set($cacheIdentifier, $pages, $cacheKeys, 86400 * 90);  // 90 days of caching
         return $pages;
     }