diff --git a/.github/workflows/integration.yml b/.github/workflows/integration.yml
index 154c6e497..8516631f4 100644
--- a/.github/workflows/integration.yml
+++ b/.github/workflows/integration.yml
@@ -74,11 +74,12 @@ jobs:
         uses: shivammathur/setup-php@2.24.0
         with:
           php-version: ${{ matrix.php-versions }}
-          tools: phpunit
-          extensions: mbstring, iconv, fileinfo, intl, sqlite, pdo_sqlite, mysql, pdo_mysql, pgsql, pdo_pgsql,
+          extensions: mbstring, iconv, fileinfo, intl, sqlite, pdo_sqlite, mysql, pdo_mysql, pgsql, pdo_pgsql, apcu
+          ini-values:
+            apc.enable_cli=on
           coverage: none
 
-      - name: Set up PHPUnit
+      - name: Set up dependencies
         working-directory: apps/${{ env.APP_NAME }}
         run: composer i --no-dev
 
@@ -91,11 +92,63 @@ jobs:
           fi
           mkdir data
           ./occ maintenance:install --verbose --database=${{ matrix.databases }} --database-name=nextcloud --database-host=127.0.0.1 --database-port=$DB_PORT --database-user=root --database-pass=rootpassword --admin-user admin --admin-pass admin
+          ./occ config:system:set hashing_default_password --value=true --type=boolean
+          ./occ config:system:set memcache.local --value="\\OC\\Memcache\\APCu"
+          ./occ config:system:set memcache.distributed --value="\\OC\\Memcache\\APCu"
           cat config/config.php
           ./occ user:list
           ./occ app:enable --force ${{ env.APP_NAME }}
+          ./occ config:system:set query_log_file --value '/home/runner/work/${{ env.APP_NAME }}/${{ env.APP_NAME }}/query.log'
           php -S localhost:8080 &
 
       - name: Run behat
         working-directory: apps/${{ env.APP_NAME }}/tests/integration
         run: ./run.sh
+
+      - name: Query count
+        if: ${{ matrix.databases == 'mysql' }}
+        uses: actions/github-script@v5
+        with:
+          github-token: ${{secrets.GITHUB_TOKEN}}
+          script: |
+            let myOutput = ''
+            let myError = ''
+
+            const options = {}
+            options.listeners = {
+              stdout: (data) => {
+                myOutput += data.toString()
+              },
+              stderr: (data) => {
+                myError += data.toString()
+              }
+            }
+            await exec.exec(`/bin/bash -c "cat /home/runner/work/${{ env.APP_NAME }}/${{ env.APP_NAME }}/query.log | wc -l"`, [], options)
+            msg = myOutput
+            const queryCount = parseInt(myOutput, 10)
+
+            myOutput = ''
+            await exec.exec('cat', ['/home/runner/work/${{ env.APP_NAME }}/${{ env.APP_NAME }}/apps/${{ env.APP_NAME }}/tests/integration/base-query-count.txt'], options)
+            const baseCount = parseInt(myOutput, 10)
+
+            const absoluteIncrease = queryCount - baseCount
+            const relativeIncrease = baseCount <= 0 ? 100 : (parseInt((absoluteIncrease / baseCount * 10000), 10) / 100)
+
+            if (absoluteIncrease >= 100 || relativeIncrease > 5) {
+              const comment = `🐢 Performance warning.\nIt looks like the query count of the integration tests increased with this PR.\nDatabase query count is now ` + queryCount + ' was ' + baseCount + ' (+' + relativeIncrease + '%)\nPlease check your code again. If you added a new test this can be expected and the base value in tests/integration/base-query-count.txt can be increased.'
+              github.rest.issues.createComment({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                body: comment
+              })
+            }
+            if (queryCount < 100) {
+              const comment = `🐈 Performance messuring seems broken. Failed to get query count.`
+              github.rest.issues.createComment({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                body: comment
+              })
+            }
\ No newline at end of file
diff --git a/lib/Controller/BoardApiController.php b/lib/Controller/BoardApiController.php
index cc974f083..a128b5c64 100644
--- a/lib/Controller/BoardApiController.php
+++ b/lib/Controller/BoardApiController.php
@@ -65,7 +65,7 @@ class BoardApiController extends ApiController {
 	public function index($details = null) {
 		$modified = $this->request->getHeader('If-Modified-Since');
 		if ($modified === null || $modified === '') {
-			$boards = $this->boardService->findAll(0, $details);
+			$boards = $this->boardService->findAll(0, $details === true);
 		} else {
 			$date = Util::parseHTTPDate($modified);
 			if (!$date) {
diff --git a/lib/DAV/DeckCalendarBackend.php b/lib/DAV/DeckCalendarBackend.php
index a1849abe9..cbb602c94 100644
--- a/lib/DAV/DeckCalendarBackend.php
+++ b/lib/DAV/DeckCalendarBackend.php
@@ -59,7 +59,7 @@ class DeckCalendarBackend {
 	}
 
 	public function getBoards(): array {
-		return $this->boardService->findAll(-1, null, false);
+		return $this->boardService->findAll(-1, false, false);
 	}
 
 	public function getBoard(int $id): Board {
diff --git a/lib/Db/AclMapper.php b/lib/Db/AclMapper.php
index cac999d4d..a74244370 100644
--- a/lib/Db/AclMapper.php
+++ b/lib/Db/AclMapper.php
@@ -52,6 +52,20 @@ class AclMapper extends DeckMapper implements IPermissionMapper {
 		return $this->findEntities($qb);
 	}
 
+	public function findIn(array $boardIds, ?int $limit = null, ?int $offset = null): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('id', 'board_id', 'type', 'participant', 'permission_edit', 'permission_share', 'permission_manage')
+			->from('deck_board_acl')
+			->where($qb->expr()->in('board_id', $qb->createParameter('boardIds')))
+			->setMaxResults($limit)
+			->setFirstResult($offset);
+
+		return iterator_to_array($this->chunkQuery($boardIds, function (array $ids) use ($qb) {
+			$qb->setParameter('boardIds', $ids, IQueryBuilder::PARAM_INT_ARRAY);
+			return $this->findEntities($qb);
+		}));
+	}
+
 	/**
 	 * @param numeric $userId
 	 * @param numeric $id
diff --git a/lib/Db/AssignmentMapper.php b/lib/Db/AssignmentMapper.php
index d7d3a1eb8..f2731431f 100644
--- a/lib/Db/AssignmentMapper.php
+++ b/lib/Db/AssignmentMapper.php
@@ -28,15 +28,13 @@ namespace OCA\Deck\Db;
 use OCA\Deck\NotFoundException;
 use OCA\Deck\Service\CirclesService;
 use OCP\AppFramework\Db\Entity;
-use OCP\AppFramework\Db\QBMapper;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IDBConnection;
 use OCP\IGroupManager;
 use OCP\IUserManager;
-use PDO;
 
-/** @template-extends QBMapper<Assignment> */
-class AssignmentMapper extends QBMapper implements IPermissionMapper {
+/** @template-extends DeckMapper<Assignment> */
+class AssignmentMapper extends DeckMapper implements IPermissionMapper {
 
 	/** @var CardMapper */
 	private $cardMapper;
@@ -60,7 +58,7 @@ class AssignmentMapper extends QBMapper implements IPermissionMapper {
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('*')
 			->from('deck_assigned_users')
-			->where($qb->expr()->eq('card_id', $qb->createNamedParameter($cardId, PDO::PARAM_INT)));
+			->where($qb->expr()->eq('card_id', $qb->createNamedParameter($cardId, IQueryBuilder::PARAM_INT)));
 		$users = $this->findEntities($qb);
 		foreach ($users as $user) {
 			$this->mapParticipant($user);
@@ -68,12 +66,29 @@ class AssignmentMapper extends QBMapper implements IPermissionMapper {
 		return $users;
 	}
 
+	public function findIn(array $cardIds): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from('deck_assigned_users')
+			->where($qb->expr()->in('card_id', $qb->createParameter('cardIds')));
+
+		$users = iterator_to_array($this->chunkQuery($cardIds, function (array $ids) use ($qb) {
+			$qb->setParameter('cardIds', $ids, IQueryBuilder::PARAM_INT_ARRAY);
+			return $this->findEntities($qb);
+		}));
+
+		foreach ($users as $user) {
+			$this->mapParticipant($user);
+		}
+		return $users;
+	}
+
 	public function findByParticipant(string $participant, $type = Assignment::TYPE_USER): array {
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('*')
 			->from('deck_assigned_users')
-			->where($qb->expr()->eq('participant', $qb->createNamedParameter($participant, PDO::PARAM_STR)))
-			->andWhere($qb->expr()->eq('type', $qb->createNamedParameter($type, PDO::PARAM_INT)));
+			->where($qb->expr()->eq('participant', $qb->createNamedParameter($participant, IQueryBuilder::PARAM_STR)))
+			->andWhere($qb->expr()->eq('type', $qb->createNamedParameter($type, IQueryBuilder::PARAM_INT)));
 		return $this->findEntities($qb);
 	}
 
@@ -132,8 +147,8 @@ class AssignmentMapper extends QBMapper implements IPermissionMapper {
 
 	private function getOrigin(Assignment $assignment) {
 		if ($assignment->getType() === Assignment::TYPE_USER) {
-			$origin = $this->userManager->get($assignment->getParticipant());
-			return $origin ? new User($origin) : null;
+			$origin = $this->userManager->userExists($assignment->getParticipant());
+			return $origin ? new User($assignment->getParticipant(), $this->userManager) : null;
 		}
 		if ($assignment->getType() === Assignment::TYPE_GROUP) {
 			$origin = $this->groupManager->get($assignment->getParticipant());
diff --git a/lib/Db/BoardMapper.php b/lib/Db/BoardMapper.php
index 5db3c3994..456152527 100644
--- a/lib/Db/BoardMapper.php
+++ b/lib/Db/BoardMapper.php
@@ -90,9 +90,6 @@ class BoardMapper extends QBMapper implements IPermissionMapper {
 			$this->boardCache[$id] = $this->findEntity($qb);
 		}
 
-		// FIXME is this necessary? it was NOT done with the old mapper
-		// $this->mapOwner($board);
-
 		// Add labels
 		if ($withLabels && $this->boardCache[$id]->getLabels() === null) {
 			$labels = $this->labelMapper->findAll($id);
@@ -160,6 +157,20 @@ class BoardMapper extends QBMapper implements IPermissionMapper {
 			$groupBoards = $this->findAllByGroups($userId, $groups, null, null, $since, $includeArchived, $before, $term);
 			$circleBoards = $this->findAllByCircles($userId, null, null, $since, $includeArchived, $before, $term);
 			$allBoards = array_unique(array_merge($userBoards, $groupBoards, $circleBoards));
+
+			// Could be moved outside
+			$acls = $this->aclMapper->findIn(array_map(function ($board) {
+				return $board->getId();
+			}, $allBoards));
+
+			/* @var Board $entry */
+			foreach ($allBoards as $entry) {
+				$boardAcls = array_values(array_filter($acls, function ($acl) use ($entry) {
+					return $acl->getBoardId() === $entry->getId();
+				}));
+				$entry->setAcl($boardAcls);
+			}
+
 			foreach ($allBoards as $board) {
 				$this->boardCache[$board->getId()] = $board;
 			}
@@ -259,11 +270,7 @@ class BoardMapper extends QBMapper implements IPermissionMapper {
 			$entry->setShared(1);
 		}
 		$entries = array_merge($entries, $sharedEntries);
-		/* @var Board $entry */
-		foreach ($entries as $entry) {
-			$acl = $this->aclMapper->findAll($entry->id);
-			$entry->setAcl($acl);
-		}
+
 		return $entries;
 	}
 
@@ -336,11 +343,6 @@ class BoardMapper extends QBMapper implements IPermissionMapper {
 		foreach ($entries as $entry) {
 			$entry->setShared(2);
 		}
-		/* @var Board $entry */
-		foreach ($entries as $entry) {
-			$acl = $this->aclMapper->findAll($entry->id);
-			$entry->setAcl($acl);
-		}
 		return $entries;
 	}
 
@@ -397,11 +399,6 @@ class BoardMapper extends QBMapper implements IPermissionMapper {
 		foreach ($entries as $entry) {
 			$entry->setShared(2);
 		}
-		/* @var Board $entry */
-		foreach ($entries as $entry) {
-			$acl = $this->aclMapper->findAll($entry->id);
-			$entry->setAcl($acl);
-		}
 		return $entries;
 	}
 
@@ -455,13 +452,11 @@ class BoardMapper extends QBMapper implements IPermissionMapper {
 	}
 
 	public function mapAcl(Acl &$acl) {
-		$userManager = $this->userManager;
 		$groupManager = $this->groupManager;
 		$acl->resolveRelation('participant', function ($participant) use (&$acl, &$userManager, &$groupManager) {
 			if ($acl->getType() === Acl::PERMISSION_TYPE_USER) {
-				$user = $userManager->get($participant);
-				if ($user !== null) {
-					return new User($user);
+				if ($this->userManager->userExists($acl->getParticipant())) {
+					return new User($acl->getParticipant(), $this->userManager);
 				}
 				$this->logger->debug('User ' . $acl->getId() . ' not found when mapping acl ' . $acl->getParticipant());
 				return null;
@@ -499,9 +494,8 @@ class BoardMapper extends QBMapper implements IPermissionMapper {
 	public function mapOwner(Board &$board) {
 		$userManager = $this->userManager;
 		$board->resolveRelation('owner', function ($owner) use (&$userManager) {
-			$user = $userManager->get($owner);
-			if ($user !== null) {
-				return new User($user);
+			if ($this->userManager->userExists($owner)) {
+				return new User($owner, $userManager);
 			}
 			return null;
 		});
diff --git a/lib/Db/CardMapper.php b/lib/Db/CardMapper.php
index d1b70c600..ac070aebf 100644
--- a/lib/Db/CardMapper.php
+++ b/lib/Db/CardMapper.php
@@ -254,13 +254,13 @@ class CardMapper extends QBMapper implements IPermissionMapper {
 		return $this->findEntities($qb);
 	}
 
-	public function findAllWithDue($boardId) {
+	public function findAllWithDue(array $boardIds) {
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('c.*')
 			->from('deck_cards', 'c')
 			->innerJoin('c', 'deck_stacks', 's', 's.id = c.stack_id')
 			->innerJoin('s', 'deck_boards', 'b', 'b.id = s.board_id')
-			->where($qb->expr()->eq('s.board_id', $qb->createNamedParameter($boardId, IQueryBuilder::PARAM_INT)))
+			->where($qb->expr()->in('s.board_id', $qb->createNamedParameter($boardIds, IQueryBuilder::PARAM_INT_ARRAY)))
 			->andWhere($qb->expr()->isNotNull('c.duedate'))
 			->andWhere($qb->expr()->eq('c.archived', $qb->createNamedParameter(false, IQueryBuilder::PARAM_BOOL)))
 			->andWhere($qb->expr()->eq('c.deleted_at', $qb->createNamedParameter(0, IQueryBuilder::PARAM_INT)))
@@ -270,14 +270,14 @@ class CardMapper extends QBMapper implements IPermissionMapper {
 		return $this->findEntities($qb);
 	}
 
-	public function findToMeOrNotAssignedCards($boardId, $username) {
+	public function findToMeOrNotAssignedCards(array $boardIds, string $username) {
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('c.*')
 			->from('deck_cards', 'c')
 			->innerJoin('c', 'deck_stacks', 's', 's.id = c.stack_id')
 			->innerJoin('s', 'deck_boards', 'b', 'b.id = s.board_id')
 			->leftJoin('c', 'deck_assigned_users', 'u', 'c.id = u.card_id')
-			->where($qb->expr()->eq('s.board_id', $qb->createNamedParameter($boardId, IQueryBuilder::PARAM_INT)))
+			->where($qb->expr()->in('s.board_id', $qb->createNamedParameter($boardIds, IQueryBuilder::PARAM_INT_ARRAY)))
 			->andWhere($qb->expr()->orX(
 				$qb->expr()->eq('u.participant', $qb->createNamedParameter($username, IQueryBuilder::PARAM_STR)),
 				$qb->expr()->isNull('u.participant'))
@@ -607,9 +607,8 @@ class CardMapper extends QBMapper implements IPermissionMapper {
 	public function mapOwner(Card &$card) {
 		$userManager = $this->userManager;
 		$card->resolveRelation('owner', function ($owner) use (&$userManager) {
-			$user = $userManager->get($owner);
-			if ($user !== null) {
-				return new User($user);
+			if ($userManager->userExists($owner)) {
+				return new User($owner, $this->userManager);
 			}
 			return null;
 		});
diff --git a/lib/Db/DeckMapper.php b/lib/Db/DeckMapper.php
index 887774409..884079447 100644
--- a/lib/Db/DeckMapper.php
+++ b/lib/Db/DeckMapper.php
@@ -23,6 +23,7 @@
 
 namespace OCA\Deck\Db;
 
+use Generator;
 use OCP\AppFramework\Db\Entity;
 use OCP\AppFramework\Db\QBMapper;
 use OCP\DB\QueryBuilder\IQueryBuilder;
@@ -35,7 +36,7 @@ abstract class DeckMapper extends QBMapper {
 
 	/**
 	 * @param $id
-	 * @return \OCP\AppFramework\Db\Entity if not found
+	 * @return T
 	 * @throws \OCP\AppFramework\Db\MultipleObjectsReturnedException
 	 * @throws \OCP\AppFramework\Db\DoesNotExistException
 	 */
@@ -47,4 +48,21 @@ abstract class DeckMapper extends QBMapper {
 
 		return $this->findEntity($qb);
 	}
+
+	/**
+	 * Helper function to split passed array into chunks of 1000 elements and
+	 * call a given callback for fetching query results
+	 *
+	 * Can be useful to limit to 1000 results per query for oracle compatiblity
+	 * but still iterate over all results
+	 */
+	public function chunkQuery(array $ids, callable $callback): Generator {
+		$limit = 1000;
+		while (!empty($ids)) {
+			$slice = array_splice($ids, 0, $limit);
+			foreach ($callback($slice) as $item) {
+				yield $item;
+			}
+		}
+	}
 }
diff --git a/lib/Db/LabelMapper.php b/lib/Db/LabelMapper.php
index 7f6de33bf..aeccef539 100644
--- a/lib/Db/LabelMapper.php
+++ b/lib/Db/LabelMapper.php
@@ -79,6 +79,19 @@ class LabelMapper extends DeckMapper implements IPermissionMapper {
 		return $this->findEntities($qb);
 	}
 
+	public function findAssignedLabelsForCards($cardIds, $limit = null, $offset = null): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('l.*', 'card_id')
+			->from($this->getTableName(), 'l')
+			->innerJoin('l', 'deck_assigned_labels', 'al', 'l.id = al.label_id')
+			->where($qb->expr()->in('card_id', $qb->createNamedParameter($cardIds, IQueryBuilder::PARAM_INT_ARRAY)))
+			->orderBy('l.id')
+			->setMaxResults($limit)
+			->setFirstResult($offset);
+
+		return $this->findEntities($qb);
+	}
+
 	/**
 	 * @param numeric $boardId
 	 * @param int|null $limit
diff --git a/lib/Db/RelationalObject.php b/lib/Db/RelationalObject.php
index bd176e1b8..1928db097 100644
--- a/lib/Db/RelationalObject.php
+++ b/lib/Db/RelationalObject.php
@@ -33,7 +33,7 @@ class RelationalObject implements JsonSerializable {
 	 * RelationalObject constructor.
 	 *
 	 * @param $primaryKey string
-	 * @param $object
+	 * @param callable|mixed $object
 	 */
 	public function __construct($primaryKey, $object) {
 		$this->primaryKey = $primaryKey;
@@ -47,16 +47,24 @@ class RelationalObject implements JsonSerializable {
 		);
 	}
 
+	public function getObject() {
+		if (is_callable($this->object)) {
+			$this->object = call_user_func($this->object, $this);
+		}
+
+		return $this->object;
+	}
+
 	/**
 	 * This method should be overwritten if object doesn't implement \JsonSerializable
 	 *
 	 * @throws \Exception
 	 */
 	public function getObjectSerialization() {
-		if ($this->object instanceof JsonSerializable) {
-			return $this->object->jsonSerialize();
+		if ($this->getObject() instanceof JsonSerializable) {
+			return $this->getObject()->jsonSerialize();
 		} else {
-			throw new \Exception('jsonSerialize is not implemented on ' . get_class($this));
+			throw new \Exception('jsonSerialize is not implemented on ' . get_class($this->getObject()));
 		}
 	}
 
diff --git a/lib/Db/StackMapper.php b/lib/Db/StackMapper.php
index 7403b6426..624c739e7 100644
--- a/lib/Db/StackMapper.php
+++ b/lib/Db/StackMapper.php
@@ -26,16 +26,19 @@ namespace OCA\Deck\Db;
 use OCP\AppFramework\Db\DoesNotExistException;
 use OCP\AppFramework\Db\Entity;
 use OCP\AppFramework\Db\MultipleObjectsReturnedException;
+use OCP\Cache\CappedMemoryCache;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IDBConnection;
 
 /** @template-extends DeckMapper<Stack> */
 class StackMapper extends DeckMapper implements IPermissionMapper {
-	private $cardMapper;
+	private CappedMemoryCache $stackCache;
+	private CardMapper $cardMapper;
 
 	public function __construct(IDBConnection $db, CardMapper $cardMapper) {
 		parent::__construct($db, 'deck_stacks', Stack::class);
 		$this->cardMapper = $cardMapper;
+		$this->stackCache = new CappedMemoryCache();
 	}
 
 
@@ -47,12 +50,17 @@ class StackMapper extends DeckMapper implements IPermissionMapper {
 	 * @throws \OCP\DB\Exception
 	 */
 	public function find($id): Stack {
+		if (isset($this->stackCache[(string)$id])) {
+			return $this->stackCache[(string)$id];
+		}
+
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('*')
 			->from($this->getTableName())
 			->where($qb->expr()->eq('id', $qb->createNamedParameter($id, IQueryBuilder::PARAM_INT)));
 
-		return $this->findEntity($qb);
+		$this->stackCache[(string)$id] = $this->findEntity($qb);
+		return $this->stackCache[(string)$id];
 	}
 
 	/**
@@ -113,9 +121,16 @@ class StackMapper extends DeckMapper implements IPermissionMapper {
 		return $this->findEntities($qb);
 	}
 
+	public function update(Entity $entity): Entity {
+		$result = parent::update($entity);
+		$this->stackCache[(string)$entity->getId()] = $result;
+		return $result;
+	}
+
 	public function delete(Entity $entity): Entity {
 		// delete cards on stack
 		$this->cardMapper->deleteByStack($entity->getId());
+		unset($this->stackCache[(string)$entity->getId()]);
 		return parent::delete($entity);
 	}
 
diff --git a/lib/Db/User.php b/lib/Db/User.php
index d595ece75..b33e264d9 100644
--- a/lib/Db/User.php
+++ b/lib/Db/User.php
@@ -23,27 +23,30 @@
 
 namespace OCA\Deck\Db;
 
-use OCP\IUser;
+use OCP\IUserManager;
 
 class User extends RelationalObject {
-	public function __construct(IUser $user) {
-		$primaryKey = $user->getUID();
-		parent::__construct($primaryKey, $user);
+	private IUserManager $userManager;
+	public function __construct($uid, IUserManager $userManager) {
+		$this->userManager = $userManager;
+		parent::__construct($uid, function ($object) {
+			return $this->userManager->get($object->getPrimaryKey());
+		});
 	}
 
 	public function getObjectSerialization() {
 		return [
-			'uid' => $this->object->getUID(),
-			'displayname' => $this->object->getDisplayName(),
-			'type' => 0
+			'uid' => $this->getObject()->getUID(),
+			'displayname' => $this->getObject()->getDisplayName(),
+			'type' => Acl::PERMISSION_TYPE_USER
 		];
 	}
 
 	public function getUID() {
-		return $this->object->getUID();
+		return $this->getPrimaryKey();
 	}
 
 	public function getDisplayName() {
-		return $this->object->getDisplayName();
+		return $this->userManager->getDisplayName($this->getPrimaryKey());
 	}
 }
diff --git a/lib/Event/AAclEvent.php b/lib/Event/AAclEvent.php
index e5534f743..f7107fe1c 100644
--- a/lib/Event/AAclEvent.php
+++ b/lib/Event/AAclEvent.php
@@ -31,7 +31,7 @@ use OCP\EventDispatcher\Event;
 
 abstract class AAclEvent extends Event {
 	private $acl;
-	
+
 	public function __construct(Acl $acl) {
 		parent::__construct();
 
@@ -41,4 +41,8 @@ abstract class AAclEvent extends Event {
 	public function getAcl(): Acl {
 		return $this->acl;
 	}
+
+	public function getBoardId(): int {
+		return $this->acl->getBoardId();
+	}
 }
diff --git a/lib/Service/BoardService.php b/lib/Service/BoardService.php
index a7388f29d..1ef0a42cf 100644
--- a/lib/Service/BoardService.php
+++ b/lib/Service/BoardService.php
@@ -79,7 +79,8 @@ class BoardService {
 	private IEventDispatcher $eventDispatcher;
 	private ChangeHelper $changeHelper;
 	private CardMapper $cardMapper;
-	private ?array $boardsCache = null;
+	private ?array $boardsCacheFull = null;
+	private ?array $boardsCachePartial = null;
 	private IURLGenerator $urlGenerator;
 	private IDBConnection $connection;
 	private BoardServiceValidator $boardServiceValidator;
@@ -147,96 +148,45 @@ class BoardService {
 	}
 
 	/**
-	 * @return array
+	 * @return Board[]
 	 */
-	public function findAll($since = -1, $details = null, $includeArchived = true) {
-		if ($this->boardsCache) {
-			return $this->boardsCache;
+	public function findAll(int $since = -1, bool $fullDetails = false, bool $includeArchived = true): array {
+		if ($this->boardsCacheFull && $fullDetails) {
+			return $this->boardsCacheFull;
 		}
+
+		if ($this->boardsCachePartial && !$fullDetails) {
+			return $this->boardsCachePartial;
+		}
+
 		$complete = $this->getUserBoards($since, $includeArchived);
-		$result = [];
-		/** @var Board $item */
-		foreach ($complete as &$item) {
-			$this->boardMapper->mapOwner($item);
-			if ($item->getAcl() !== null) {
-				foreach ($item->getAcl() as &$acl) {
-					$this->boardMapper->mapAcl($acl);
-				}
-			}
-			if ($details !== null) {
-				$this->enrichWithStacks($item);
-				$this->enrichWithLabels($item);
-				$this->enrichWithUsers($item);
-			}
-			$permissions = $this->permissionService->matchPermissions($item);
-			$item->setPermissions([
-				'PERMISSION_READ' => $permissions[Acl::PERMISSION_READ] ?? false,
-				'PERMISSION_EDIT' => $permissions[Acl::PERMISSION_EDIT] ?? false,
-				'PERMISSION_MANAGE' => $permissions[Acl::PERMISSION_MANAGE] ?? false,
-				'PERMISSION_SHARE' => $permissions[Acl::PERMISSION_SHARE] ?? false
-			]);
-			$this->enrichWithBoardSettings($item);
-			$result[$item->getId()] = $item;
-		}
-		$this->boardsCache = $result;
-		return array_values($result);
+		return $this->enrichBoards($complete, $fullDetails);
 	}
 
 	/**
-	 * @param $boardId
-	 * @return Board
 	 * @throws DoesNotExistException
 	 * @throws \OCA\Deck\NoPermissionException
 	 * @throws \OCP\AppFramework\Db\MultipleObjectsReturnedException
 	 * @throws BadRequestException
 	 */
-	public function find($boardId) {
+	public function find(int $boardId, bool $fullDetails = true): Board {
 		$this->boardServiceValidator->check(compact('boardId'));
-		if ($this->boardsCache && isset($this->boardsCache[$boardId])) {
-			return $this->boardsCache[$boardId];
+
+		if (isset($this->boardsCacheFull[$boardId]) && $fullDetails) {
+			return $this->boardsCacheFull[$boardId];
 		}
-		if (is_numeric($boardId) === false) {
-			throw new BadRequestException('board id must be a number');
+
+		if (isset($this->boardsCachePartial[$boardId]) && !$fullDetails) {
+			return $this->boardsCachePartial[$boardId];
 		}
 
 		$this->permissionService->checkPermission($this->boardMapper, $boardId, Acl::PERMISSION_READ);
 		/** @var Board $board */
 		$board = $this->boardMapper->find($boardId, true, true);
-		$this->boardMapper->mapOwner($board);
-		if ($board->getAcl() !== null) {
-			foreach ($board->getAcl() as $acl) {
-				if ($acl !== null) {
-					$this->boardMapper->mapAcl($acl);
-				}
-			}
-		}
-		$permissions = $this->permissionService->matchPermissions($board);
-		$board->setPermissions([
-			'PERMISSION_READ' => $permissions[Acl::PERMISSION_READ] ?? false,
-			'PERMISSION_EDIT' => $permissions[Acl::PERMISSION_EDIT] ?? false,
-			'PERMISSION_MANAGE' => $permissions[Acl::PERMISSION_MANAGE] ?? false,
-			'PERMISSION_SHARE' => $permissions[Acl::PERMISSION_SHARE] ?? false
-		]);
-		$this->enrichWithUsers($board);
-		$this->enrichWithBoardSettings($board);
-		$this->enrichWithActiveSessions($board);
-		$this->boardsCache[$board->getId()] = $board;
+		[$board] = $this->enrichBoards([$board], $fullDetails);
 		return $board;
 	}
 
-	/**
-	 * @return array
-	 */
-	private function getBoardPrerequisites() {
-		$groups = $this->groupManager->getUserGroupIds(
-			$this->userManager->get($this->userId)
-		);
-		return [
-			'user' => $this->userId,
-			'groups' => $groups
-		];
-	}
-
 	/**
 	 * @param $mapper
 	 * @param $id
@@ -456,7 +406,7 @@ class BoardService {
 
 	public function enrichWithActiveSessions(Board $board) {
 		$sessions = $this->sessionMapper->findAllActive($board->getId());
-		
+
 		$board->setActiveSessions(array_values(
 			array_unique(
 				array_map(function (Session $session) {
@@ -691,6 +641,45 @@ class BoardService {
 		return $board;
 	}
 
+	/** @param Board[] $boards */
+	private function enrichBoards(array $boards, bool $fullDetails = true): array {
+		$result = [];
+		foreach ($boards as $board) {
+			// FIXME The enrichment in here could make use of combined queries
+			$this->boardMapper->mapOwner($board);
+			if ($board->getAcl() !== null) {
+				foreach ($board->getAcl() as &$acl) {
+					$this->boardMapper->mapAcl($acl);
+				}
+			}
+
+			$permissions = $this->permissionService->matchPermissions($board);
+			$board->setPermissions([
+				'PERMISSION_READ' => $permissions[Acl::PERMISSION_READ] ?? false,
+				'PERMISSION_EDIT' => $permissions[Acl::PERMISSION_EDIT] ?? false,
+				'PERMISSION_MANAGE' => $permissions[Acl::PERMISSION_MANAGE] ?? false,
+				'PERMISSION_SHARE' => $permissions[Acl::PERMISSION_SHARE] ?? false
+			]);
+
+			if ($fullDetails) {
+				$this->enrichWithStacks($board);
+				$this->enrichWithLabels($board);
+				$this->enrichWithUsers($board);
+				$this->enrichWithBoardSettings($board);
+				$this->enrichWithActiveSessions($board);
+			}
+
+			// Cache for further usage
+			if ($fullDetails) {
+				$this->boardsCacheFull[$board->getId()] = $board;
+			} else {
+				$this->boardsCachePartial[$board->getId()] = $board;
+			}
+		}
+
+		return $boards;
+	}
+
 	private function enrichWithStacks($board, $since = -1) {
 		$stacks = $this->stackMapper->findAll($board->getId(), null, null, $since);
 
@@ -713,7 +702,7 @@ class BoardService {
 
 	private function enrichWithUsers($board, $since = -1) {
 		$boardUsers = $this->permissionService->findUsers($board->getId());
-		if (\count($boardUsers) === 0) {
+		if ($boardUsers === null || \count($boardUsers) === 0) {
 			return;
 		}
 		$board->setUsers(array_values($boardUsers));
@@ -723,10 +712,6 @@ class BoardService {
 		return $this->urlGenerator->linkToRouteAbsolute('deck.page.index') . '#' . $endpoint;
 	}
 
-	private function clearBoardsCache() {
-		$this->boardsCache = null;
-	}
-
 	/**
 	 * Clean a given board data from the Cache
 	 */
@@ -735,7 +720,8 @@ class BoardService {
 		$boardOwnerId = $board->getOwner();
 
 		$this->boardMapper->flushCache($boardId, $boardOwnerId);
-		unset($this->boardsCache[$boardId]);
+		unset($this->boardsCacheFull[$boardId]);
+		unset($this->boardsCachePartial[$boardId]);
 	}
 
 	private function enrichWithCards($board) {
diff --git a/lib/Service/CardService.php b/lib/Service/CardService.php
index 95dbcf59a..b44a094d9 100644
--- a/lib/Service/CardService.php
+++ b/lib/Service/CardService.php
@@ -28,11 +28,13 @@ namespace OCA\Deck\Service;
 
 use OCA\Deck\Activity\ActivityManager;
 use OCA\Deck\Activity\ChangeSet;
+use OCA\Deck\Db\Assignment;
 use OCA\Deck\Db\AssignmentMapper;
 use OCA\Deck\Db\Card;
 use OCA\Deck\Db\CardMapper;
 use OCA\Deck\Db\Acl;
 use OCA\Deck\Db\ChangeHelper;
+use OCA\Deck\Db\Label;
 use OCA\Deck\Db\StackMapper;
 use OCA\Deck\Event\CardCreatedEvent;
 use OCA\Deck\Event\CardDeletedEvent;
@@ -114,32 +116,52 @@ class CardService {
 		$this->cardServiceValidator = $cardServiceValidator;
 	}
 
-	public function enrich($card) {
-		$cardId = $card->getId();
-		$this->cardMapper->mapOwner($card);
-		$card->setAssignedUsers($this->assignedUsersMapper->findAll($cardId));
-		$card->setLabels($this->labelMapper->findAssignedLabelsForCard($cardId));
-		$card->setAttachmentCount($this->attachmentService->count($cardId));
+	public function enrichCards($cards) {
 		$user = $this->userManager->get($this->currentUser);
-		$lastRead = $this->commentsManager->getReadMark('deckCard', (string)$card->getId(), $user);
-		$countUnreadComments = $this->commentsManager->getNumberOfCommentsForObject('deckCard', (string)$card->getId(), $lastRead);
-		$countComments = $this->commentsManager->getNumberOfCommentsForObject('deckCard', (string)$card->getId());
-		$card->setCommentsUnread($countUnreadComments);
-		$card->setCommentsCount($countComments);
 
-		$stack = $this->stackMapper->find($card->getStackId());
-		$board = $this->boardService->find($stack->getBoardId());
-		$card->setRelatedStack($stack);
-		$card->setRelatedBoard($board);
+		$cardIds = array_map(function (Card $card) use ($user) {
+			// Everything done in here might be heavy as it is executed for every card
+			$cardId = $card->getId();
+			$this->cardMapper->mapOwner($card);
+
+			$card->setAttachmentCount($this->attachmentService->count($cardId));
+
+			// TODO We should find a better way just to get the comment count so we can save 1-3 queries per card here
+			$countComments = $this->commentsManager->getNumberOfCommentsForObject('deckCard', (string)$card->getId());
+			$lastRead = $countComments > 0 ? $this->commentsManager->getReadMark('deckCard', (string)$card->getId(), $user) : null;
+			$countUnreadComments = $lastRead ? $this->commentsManager->getNumberOfCommentsForObject('deckCard', (string)$card->getId(), $lastRead) : 0;
+			$card->setCommentsUnread($countUnreadComments);
+			$card->setCommentsCount($countComments);
+
+			$stack = $this->stackMapper->find($card->getStackId());
+			$board = $this->boardService->find($stack->getBoardId(), false);
+			$card->setRelatedStack($stack);
+			$card->setRelatedBoard($board);
+
+			return $card->getId();
+		}, $cards);
+
+		$assignedLabels = $this->labelMapper->findAssignedLabelsForCards($cardIds);
+		$assignedUsers = $this->assignedUsersMapper->findIn($cardIds);
+
+		foreach ($cards as $card) {
+			$cardLabels = array_values(array_filter($assignedLabels, function (Label $label) use ($card) {
+				return $label->getCardId() === $card->getId();
+			}));
+			$cardAssignedUsers = array_values(array_filter($assignedUsers, function (Assignment $assignment) use ($card) {
+				return $assignment->getCardId() === $card->getId();
+			}));
+			$card->setLabels($cardLabels);
+			$card->setAssignedUsers($cardAssignedUsers);
+		}
+
+		return $cards;
 	}
-
 	public function fetchDeleted($boardId) {
 		$this->cardServiceValidator->check(compact('boardId'));
 		$this->permissionService->checkPermission($this->boardMapper, $boardId, Acl::PERMISSION_READ);
 		$cards = $this->cardMapper->findDeleted($boardId);
-		foreach ($cards as $card) {
-			$this->enrich($card);
-		}
+		$this->enrichCards($cards);
 		return $cards;
 	}
 
@@ -153,16 +175,17 @@ class CardService {
 	public function find(int $cardId) {
 		$this->permissionService->checkPermission($this->cardMapper, $cardId, Acl::PERMISSION_READ);
 		$card = $this->cardMapper->find($cardId);
-		$assignedUsers = $this->assignedUsersMapper->findAll($card->getId());
+		[$card] = $this->enrichCards([$card]);
+
+		// Attachments are only enriched on individual card fetching
 		$attachments = $this->attachmentService->findAll($cardId, true);
 		if ($this->request->getParam('apiVersion') === '1.0') {
 			$attachments = array_filter($attachments, function ($attachment) {
 				return $attachment->getType() === 'deck_file';
 			});
 		}
-		$card->setAssignedUsers($assignedUsers);
 		$card->setAttachments($attachments);
-		$this->enrich($card);
+
 		return $card;
 	}
 
@@ -174,9 +197,7 @@ class CardService {
 			return [];
 		}
 		$cards = $this->cardMapper->findCalendarEntries($boardId);
-		foreach ($cards as $card) {
-			$this->enrich($card);
-		}
+		$this->enrichCards($cards);
 		return $cards;
 	}
 
diff --git a/lib/Service/DefaultBoardService.php b/lib/Service/DefaultBoardService.php
index a9f31d0ac..5698994d6 100644
--- a/lib/Service/DefaultBoardService.php
+++ b/lib/Service/DefaultBoardService.php
@@ -62,9 +62,8 @@ class DefaultBoardService {
 	 */
 	public function checkFirstRun($userId): bool {
 		$firstRun = $this->config->getUserValue($userId, Application::APP_ID, 'firstRun', 'yes');
-		$userBoards = $this->boardMapper->findAllByUser($userId);
 
-		if ($firstRun === 'yes' && count($userBoards) === 0) {
+		if ($firstRun === 'yes') {
 			try {
 				$this->config->setUserValue($userId, Application::APP_ID, 'firstRun', 'no');
 			} catch (PreConditionNotMetException $e) {
diff --git a/lib/Service/OverviewService.php b/lib/Service/OverviewService.php
index 8b8b07511..7c1f4479f 100644
--- a/lib/Service/OverviewService.php
+++ b/lib/Service/OverviewService.php
@@ -28,7 +28,7 @@ declare(strict_types=1);
 namespace OCA\Deck\Service;
 
 use OCA\Deck\Db\AssignmentMapper;
-use OCA\Deck\Db\Card;
+use OCA\Deck\Db\Board;
 use OCA\Deck\Db\CardMapper;
 use OCA\Deck\Model\CardDetails;
 use OCP\Comments\ICommentsManager;
@@ -37,6 +37,7 @@ use OCA\Deck\Db\LabelMapper;
 use OCP\IUserManager;
 
 class OverviewService {
+	private CardService $cardService;
 	private BoardMapper $boardMapper;
 	private LabelMapper $labelMapper;
 	private CardMapper $cardMapper;
@@ -46,6 +47,7 @@ class OverviewService {
 	private AttachmentService $attachmentService;
 
 	public function __construct(
+		CardService $cardService,
 		BoardMapper $boardMapper,
 		LabelMapper $labelMapper,
 		CardMapper $cardMapper,
@@ -54,6 +56,7 @@ class OverviewService {
 		ICommentsManager $commentsManager,
 		AttachmentService $attachmentService
 	) {
+		$this->cardService = $cardService;
 		$this->boardMapper = $boardMapper;
 		$this->labelMapper = $labelMapper;
 		$this->cardMapper = $cardMapper;
@@ -63,66 +66,43 @@ class OverviewService {
 		$this->attachmentService = $attachmentService;
 	}
 
-	public function enrich(Card $card, string $userId): void {
-		$cardId = $card->getId();
-
-		$this->cardMapper->mapOwner($card);
-		$card->setAssignedUsers($this->assignedUsersMapper->findAll($cardId));
-		$card->setLabels($this->labelMapper->findAssignedLabelsForCard($cardId));
-		$card->setAttachmentCount($this->attachmentService->count($cardId));
-
-		$user = $this->userManager->get($userId);
-		if ($user !== null) {
-			$lastRead = $this->commentsManager->getReadMark('deckCard', (string)$card->getId(), $user);
-			$count = $this->commentsManager->getNumberOfCommentsForObject('deckCard', (string)$card->getId(), $lastRead);
-			$card->setCommentsUnread($count);
-		}
-	}
-
-	public function findAllWithDue(string $userId): array {
-		$userBoards = $this->boardMapper->findAllForUser($userId);
-		$allDueCards = [];
-		foreach ($userBoards as $userBoard) {
-			$allDueCards[] = array_map(function ($card) use ($userBoard, $userId) {
-				$this->enrich($card, $userId);
-				return (new CardDetails($card, $userBoard))->jsonSerialize();
-			}, $this->cardMapper->findAllWithDue($userBoard->getId()));
-		}
-		return array_merge(...$allDueCards);
-	}
-
 	public function findUpcomingCards(string $userId): array {
 		$userBoards = $this->boardMapper->findAllForUser($userId);
+
+		$boardOwnerIds = array_filter(array_map(function (Board $board) {
+			return count($board->getAcl()) === 0 ? $board->getId() : null;
+		}, $userBoards));
+		$boardSharedIds = array_filter(array_map(function (Board $board) {
+			return count($board->getAcl()) > 0 ? $board->getId() : null;
+		}, $userBoards));
+
+		$foundCards = array_merge(
+			// private board: get cards with due date
+			$this->cardMapper->findAllWithDue($boardOwnerIds),
+			// shared board: get all my assigned or unassigned cards
+			$this->cardMapper->findToMeOrNotAssignedCards($boardSharedIds, $userId)
+		);
+
+		$this->cardService->enrichCards($foundCards);
 		$overview = [];
-		foreach ($userBoards as $userBoard) {
-			if (count($userBoard->getAcl()) === 0) {
-				// private board: get cards with due date
-				$cards = $this->cardMapper->findAllWithDue($userBoard->getId());
-			} else {
-				// shared board: get all my assigned or unassigned cards
-				$cards = $this->cardMapper->findToMeOrNotAssignedCards($userBoard->getId(), $userId);
+		foreach ($foundCards as $card) {
+			$diffDays = $card->getDaysUntilDue();
+
+			$key = 'later';
+			if ($diffDays === null) {
+				$key = 'nodue';
+			} elseif ($diffDays < 0) {
+				$key = 'overdue';
+			} elseif ($diffDays === 0) {
+				$key = 'today';
+			} elseif ($diffDays === 1) {
+				$key = 'tomorrow';
+			} elseif ($diffDays <= 7) {
+				$key = 'nextSevenDays';
 			}
 
-			foreach ($cards as $card) {
-				$this->enrich($card, $userId);
-				$diffDays = $card->getDaysUntilDue();
-
-				$key = 'later';
-				if ($diffDays === null) {
-					$key = 'nodue';
-				} elseif ($diffDays < 0) {
-					$key = 'overdue';
-				} elseif ($diffDays === 0) {
-					$key = 'today';
-				} elseif ($diffDays === 1) {
-					$key = 'tomorrow';
-				} elseif ($diffDays <= 7) {
-					$key = 'nextSevenDays';
-				}
-
-				$card = (new CardDetails($card, $userBoard));
-				$overview[$key][] = $card->jsonSerialize();
-			}
+			$card = (new CardDetails($card, $card->getRelatedBoard()));
+			$overview[$key][] = $card->jsonSerialize();
 		}
 		return $overview;
 	}
diff --git a/lib/Service/PermissionService.php b/lib/Service/PermissionService.php
index d0630a633..2956b3234 100644
--- a/lib/Service/PermissionService.php
+++ b/lib/Service/PermissionService.php
@@ -143,7 +143,7 @@ class PermissionService {
 	 * @return bool
 	 * @throws NoPermissionException
 	 */
-	public function checkPermission($mapper, $id, $permission, $userId = null) {
+	public function checkPermission($mapper, $id, $permission, $userId = null): bool {
 		$boardId = $id;
 		if ($mapper instanceof IPermissionMapper && !($mapper instanceof BoardMapper)) {
 			$boardId = $mapper->findBoardId($id);
@@ -153,23 +153,11 @@ class PermissionService {
 			throw new NoPermissionException('Permission denied');
 		}
 
-		if ($permission === Acl::PERMISSION_SHARE && $this->shareManager->sharingDisabledForUser($this->userId)) {
-			throw new NoPermissionException('Permission denied');
-		}
-
-		if ($this->userIsBoardOwner($boardId, $userId)) {
+		$permissions = $this->getPermissions($boardId);
+		if ($permissions[$permission] === true) {
 			return true;
 		}
 
-		try {
-			$acls = $this->getBoard($boardId)->getAcl() ?? [];
-			$result = $this->userCan($acls, $permission, $userId);
-			if ($result) {
-				return true;
-			}
-		} catch (DoesNotExistException | MultipleObjectsReturnedException $e) {
-		}
-
 		// Throw NoPermission to not leak information about existing entries
 		throw new NoPermissionException('Permission denied');
 	}
@@ -260,22 +248,20 @@ class PermissionService {
 		}
 
 		$users = [];
-		$owner = $this->userManager->get($board->getOwner());
-		if ($owner === null) {
+		if (!$this->userManager->userExists($board->getOwner())) {
 			$this->logger->info('No owner found for board ' . $board->getId());
 		} else {
-			$users[$owner->getUID()] = new User($owner);
+			$users[$board->getOwner()] = new User($board->getOwner(), $this->userManager);
 		}
 		$acls = $this->aclMapper->findAll($boardId);
 		/** @var Acl $acl */
 		foreach ($acls as $acl) {
 			if ($acl->getType() === Acl::PERMISSION_TYPE_USER) {
-				$user = $this->userManager->get($acl->getParticipant());
-				if ($user === null) {
+				if (!$this->userManager->userExists($acl->getParticipant())) {
 					$this->logger->info('No user found for acl rule ' . $acl->getId());
 					continue;
 				}
-				$users[$user->getUID()] = new User($user);
+				$users[$acl->getParticipant()] = new User($acl->getParticipant(), $this->userManager);
 			}
 			if ($acl->getType() === Acl::PERMISSION_TYPE_GROUP) {
 				$group = $this->groupManager->get($acl->getParticipant());
@@ -284,7 +270,7 @@ class PermissionService {
 					continue;
 				}
 				foreach ($group->getUsers() as $user) {
-					$users[$user->getUID()] = new User($user);
+					$users[$user->getUID()] = new User($user->getUID(), $this->userManager);
 				}
 			}
 
@@ -305,7 +291,7 @@ class PermissionService {
 						if ($user === null) {
 							$this->logger->info('No user found for circle member ' . $member->getUserId());
 						} else {
-							$users[$member->getUserId()] = new User($user);
+							$users[$member->getUserId()] = new User($member->getUserId(), $this->userManager);
 						}
 					}
 				} catch (\Exception $e) {
diff --git a/lib/Service/SearchService.php b/lib/Service/SearchService.php
index 11bfedf33..421747403 100644
--- a/lib/Service/SearchService.php
+++ b/lib/Service/SearchService.php
@@ -82,11 +82,7 @@ class SearchService {
 		}, $boards);
 		$matchedCards = $this->cardMapper->search($boardIds, $this->filterStringParser->parse($term), $limit, $cursor);
 
-		$self = $this;
-		return array_map(function (Card $card) use ($self) {
-			$self->cardService->enrich($card);
-			return $card;
-		}, $matchedCards);
+		return $this->cardService->enrichCards($matchedCards);
 	}
 
 	public function searchBoards(string $term, ?int $limit, ?int $cursor): array {
@@ -117,7 +113,8 @@ class SearchService {
 			$comment = $this->commentsManager->get($cardRow['comment_id']);
 			unset($cardRow['comment_id']);
 			$card = Card::fromRow($cardRow);
-			$self->cardService->enrich($card);
+			// TODO: Only perform one enrich call here
+			$self->cardService->enrichCards([$card]);
 			$user = $this->userManager->get($comment->getActorId());
 			$displayName = $user ? $user->getDisplayName() : '';
 			return new CommentSearchResultEntry($comment->getId(), $comment->getMessage(), $displayName, $card, $this->urlGenerator, $this->l10n);
diff --git a/lib/Service/StackService.php b/lib/Service/StackService.php
index d41c00de0..83ca7d23e 100644
--- a/lib/Service/StackService.php
+++ b/lib/Service/StackService.php
@@ -94,9 +94,9 @@ class StackService {
 			return;
 		}
 
+		$this->cardService->enrichCards($cards);
 		$cards = array_map(
 			function (Card $card): CardDetails {
-				$this->cardService->enrich($card);
 				return new CardDetails($card);
 			},
 			$cards
diff --git a/tests/integration/base-query-count.txt b/tests/integration/base-query-count.txt
new file mode 100644
index 000000000..bd7d9524a
--- /dev/null
+++ b/tests/integration/base-query-count.txt
@@ -0,0 +1 @@
+61324
diff --git a/tests/integration/features/bootstrap/ServerContext.php b/tests/integration/features/bootstrap/ServerContext.php
index 6880f764c..f7c192384 100644
--- a/tests/integration/features/bootstrap/ServerContext.php
+++ b/tests/integration/features/bootstrap/ServerContext.php
@@ -40,7 +40,6 @@ class ServerContext implements Context {
 	}
 
 	public function getCookieJar(): CookieJar {
-		echo $this->currentUser;
 		return $this->cookieJar;
 	}
 
diff --git a/tests/integration/run.sh b/tests/integration/run.sh
index bcabf9ed7..1dfe35b70 100755
--- a/tests/integration/run.sh
+++ b/tests/integration/run.sh
@@ -27,16 +27,16 @@ if [ -z "$EXECUTOR_NUMBER" ]; then
 fi
 PORT=$((9090 + $EXECUTOR_NUMBER))
 echo $PORT
-php -S localhost:$PORT -t $OC_PATH &
+php -q -S localhost:$PORT -t $OC_PATH &
 PHPPID=$!
 echo $PHPPID
 
 export TEST_SERVER_URL="http://localhost:$PORT/ocs/"
 
-vendor/bin/behat $SCENARIO_TO_RUN
+vendor/bin/behat --colors $SCENARIO_TO_RUN
 RESULT=$?
 
-kill $PHPPID
+kill -9 $PHPPID
 
 echo "runsh: Exit code: $RESULT"
 exit $RESULT
diff --git a/tests/unit/Db/UserTest.php b/tests/unit/Db/UserTest.php
index 8f7e84816..290331f6d 100644
--- a/tests/unit/Db/UserTest.php
+++ b/tests/unit/Db/UserTest.php
@@ -24,6 +24,7 @@
 namespace OCA\Deck\Db;
 
 use OCP\IUser;
+use OCP\IUserManager;
 
 class UserTest extends \Test\TestCase {
 	public function testGroupObjectSerialize() {
@@ -35,7 +36,11 @@ class UserTest extends \Test\TestCase {
 		$user->expects($this->any())
 			->method('getDisplayName')
 			->willReturn('myuser displayname');
-		$userRelationalObject = new User($user);
+		$userManager = $this->createMock(IUserManager::class);
+		$userManager->expects($this->any())
+			->method('get')
+			->willReturn($user);
+		$userRelationalObject = new User('myuser', $userManager);
 		$expected = [
 			'uid' => 'myuser',
 			'displayname' => 'myuser displayname',
@@ -53,7 +58,11 @@ class UserTest extends \Test\TestCase {
 		$user->expects($this->any())
 			->method('getDisplayName')
 			->willReturn('myuser displayname');
-		$userRelationalObject = new User($user);
+		$userManager = $this->createMock(IUserManager::class);
+		$userManager->expects($this->any())
+			->method('get')
+			->willReturn($user);
+		$userRelationalObject = new User('myuser', $userManager);
 		$expected = [
 			'uid' => 'myuser',
 			'displayname' => 'myuser displayname',
diff --git a/tests/unit/Notification/NotificationHelperTest.php b/tests/unit/Notification/NotificationHelperTest.php
index c4f0fd9cd..4e0803dcd 100644
--- a/tests/unit/Notification/NotificationHelperTest.php
+++ b/tests/unit/Notification/NotificationHelperTest.php
@@ -37,6 +37,7 @@ use OCP\IConfig;
 use OCP\IGroup;
 use OCP\IGroupManager;
 use OCP\IUser;
+use OCP\IUserManager;
 use OCP\Notification\IManager;
 use OCP\Notification\INotification;
 use PHPUnit\Framework\MockObject\MockObject;
@@ -219,8 +220,9 @@ class NotificationHelperTest extends \Test\TestCase {
 			'title' => 'MyCardTitle',
 			'duedate' => '2020-12-24'
 		]);
+		$userManager = $this->createMock(IUserManager::class);
 		$card->setAssignedUsers([
-			new User($users[0])
+			new User($users[0]->getUID(), $userManager)
 		]);
 		$this->cardMapper->expects($this->once())
 			->method('findBoardId')
@@ -308,8 +310,9 @@ class NotificationHelperTest extends \Test\TestCase {
 			'title' => 'MyCardTitle',
 			'duedate' => '2020-12-24'
 		]);
+		$userManager = $this->createMock(IUserManager::class);
 		$card->setAssignedUsers([
-			new User($users[0])
+			new User($users[0]->getUID(), $userManager)
 		]);
 		$this->cardMapper->expects($this->once())
 			->method('findBoardId')
diff --git a/tests/unit/Service/CardServiceTest.php b/tests/unit/Service/CardServiceTest.php
index 8c8691977..1952747b3 100644
--- a/tests/unit/Service/CardServiceTest.php
+++ b/tests/unit/Service/CardServiceTest.php
@@ -24,6 +24,7 @@
 namespace OCA\Deck\Service;
 
 use OCA\Deck\Activity\ActivityManager;
+use OCA\Deck\Db\Assignment;
 use OCA\Deck\Db\AssignmentMapper;
 use OCA\Deck\Db\Board;
 use OCA\Deck\Db\Card;
@@ -155,7 +156,8 @@ class CardServiceTest extends TestCase {
 			->method('getNumberOfCommentsForObject')
 			->willReturn(0);
 		$boardMock = $this->createMock(Board::class);
-		$stackMock = $this->createMock(Stack::class);
+		$stackMock = new Stack();
+		$stackMock->setBoardId(1234);
 		$this->stackMapper->expects($this->any())
 			->method('find')
 			->willReturn($stackMock);
@@ -168,13 +170,21 @@ class CardServiceTest extends TestCase {
 			->method('find')
 			->with(123)
 			->willReturn($card);
+		$a1 = new Assignment();
+		$a1->setCardId(1337);
+		$a1->setType(0);
+		$a1->setParticipant('user1');
+		$a2 = new Assignment();
+		$a2->setCardId(1337);
+		$a2->setType(0);
+		$a2->setParticipant('user2');
 		$this->assignedUsersMapper->expects($this->any())
-			->method('findAll')
-			->with(1337)
-			->willReturn(['user1', 'user2']);
+			->method('findIn')
+			->with([1337])
+			->willReturn([$a1, $a2]);
 		$cardExpected = new Card();
 		$cardExpected->setId(1337);
-		$cardExpected->setAssignedUsers(['user1', 'user2']);
+		$cardExpected->setAssignedUsers([$a1, $a2]);
 		$cardExpected->setRelatedBoard($boardMock);
 		$cardExpected->setRelatedStack($stackMock);
 		$cardExpected->setLabels([]);
diff --git a/tests/unit/Service/DefaultBoardServiceTest.php b/tests/unit/Service/DefaultBoardServiceTest.php
index 804bb6226..2e38c83bc 100644
--- a/tests/unit/Service/DefaultBoardServiceTest.php
+++ b/tests/unit/Service/DefaultBoardServiceTest.php
@@ -83,10 +83,6 @@ class DefaultBoardServiceTest extends TestCase {
 			->method('getUserValue')
 			->willReturn('yes');
 
-		$this->boardMapper->expects($this->once())
-			->method('findAllByUser')
-			->willReturn($userBoards);
-
 		$this->config->expects($this->once())
 			->method('setUserValue');
 
@@ -107,10 +103,6 @@ class DefaultBoardServiceTest extends TestCase {
 			->method('getUserValue')
 			->willReturn('no');
 
-		$this->boardMapper->expects($this->once())
-			->method('findAllByUser')
-			->willReturn($userBoards);
-
 		$result = $this->service->checkFirstRun($this->userId);
 		$this->assertEquals($result, false);
 	}
diff --git a/tests/unit/Service/Importer/Systems/TrelloJsonServiceTest.php b/tests/unit/Service/Importer/Systems/TrelloJsonServiceTest.php
index 46c0799d1..a1e18b11c 100644
--- a/tests/unit/Service/Importer/Systems/TrelloJsonServiceTest.php
+++ b/tests/unit/Service/Importer/Systems/TrelloJsonServiceTest.php
@@ -30,6 +30,9 @@ use OCP\IUserManager;
 use OCP\Server;
 use PHPUnit\Framework\MockObject\MockObject;
 
+/**
+ * @group DB
+ */
 class TrelloJsonServiceTest extends \Test\TestCase {
 	private TrelloJsonService $service;
 	/** @var IURLGenerator|MockObject */
@@ -57,7 +60,7 @@ class TrelloJsonServiceTest extends \Test\TestCase {
 	}
 
 	public function testValidateUsersWithInvalidUser() {
-		$this->expectErrorMessage('Trello user trello_user not found in property "members" of json data');
+		$this->expectExceptionMessage('Trello user trello_user not found in property "members" of json data');
 		$importService = $this->createMock(BoardImportService::class);
 		$importService
 			->method('getConfig')
diff --git a/tests/unit/Service/PermissionServiceTest.php b/tests/unit/Service/PermissionServiceTest.php
index 0994a778e..d0d236b2e 100644
--- a/tests/unit/Service/PermissionServiceTest.php
+++ b/tests/unit/Service/PermissionServiceTest.php
@@ -236,6 +236,11 @@ class PermissionServiceTest extends \Test\TestCase {
 		$board->setAcl($this->getAcls($boardId));
 		$this->boardMapper->expects($this->any())->method('find')->willReturn($board);
 
+		$this->aclMapper->expects($this->any())
+			->method('findAll')
+			->with($boardId)
+			->willReturn($this->getAcls($boardId));
+
 		$this->shareManager->expects($this->any())
 			->method('sharingDisabledForUser')
 			->willReturn(false);
@@ -262,12 +267,17 @@ class PermissionServiceTest extends \Test\TestCase {
 			$this->boardMapper->expects($this->any())->method('find')->willReturn($board);
 		}
 
+		$this->aclMapper->expects($this->any())
+			->method('findAll')
+			->with($boardId)
+			->willReturn($this->getAcls($boardId));
+
 		if ($result) {
-			$actual = $this->service->checkPermission($mapper, 1234, $permission);
+			$actual = $this->service->checkPermission($mapper, $boardId, $permission);
 			$this->assertTrue($actual);
 		} else {
 			$this->expectException(NoPermissionException::class);
-			$this->service->checkPermission($mapper, 1234, $permission);
+			$this->service->checkPermission($mapper, $boardId, $permission);
 		}
 	}
 
@@ -340,7 +350,7 @@ class PermissionServiceTest extends \Test\TestCase {
 		$aclGroup->setParticipant('group1');
 
 		$board = $this->createMock(Board::class);
-		$board->expects($this->once())
+		$board->expects($this->any())
 			->method('__call')
 			->with('getOwner', [])
 			->willReturn('user1');
@@ -352,8 +362,8 @@ class PermissionServiceTest extends \Test\TestCase {
 			->method('find')
 			->with(123)
 			->willReturn($board);
-		$this->userManager->expects($this->exactly(2))
-			->method('get')
+		$this->userManager->expects($this->any())
+			->method('userExists')
 			->withConsecutive(['user1'], ['user2'])
 			->willReturnOnConsecutiveCalls($user1, $user2);
 
@@ -367,9 +377,9 @@ class PermissionServiceTest extends \Test\TestCase {
 			->willReturn($group);
 		$users = $this->service->findUsers(123);
 		$this->assertEquals([
-			'user1' => new User($user1),
-			'user2' => new User($user2),
-			'user3' => new User($user3),
+			'user1' => new User($user1->getUID(), $this->userManager),
+			'user2' => new User($user2->getUID(), $this->userManager),
+			'user3' => new User($user3->getUID(), $this->userManager),
 		], $users);
 	}
 }
diff --git a/tests/unit/Service/StackServiceTest.php b/tests/unit/Service/StackServiceTest.php
index af0a720ac..78737ab68 100644
--- a/tests/unit/Service/StackServiceTest.php
+++ b/tests/unit/Service/StackServiceTest.php
@@ -110,10 +110,12 @@ class StackServiceTest extends TestCase {
 	public function testFindAll() {
 		$this->permissionService->expects($this->once())->method('checkPermission');
 		$this->stackMapper->expects($this->once())->method('findAll')->willReturn($this->getStacks());
-		$this->cardService->expects($this->atLeastOnce())->method('enrich')->will(
+		$this->cardService->expects($this->atLeastOnce())->method('enrichCards')->will(
 					$this->returnCallback(
-						function ($card) {
-							$card->setLabels($this->getLabels()[$card->getId()]);
+						function ($cards) {
+							foreach ($cards as $card) {
+								$card->setLabels($this->getLabels()[$card->getId()]);
+							}
 						}
 					)
 				);
diff --git a/tests/unit/controller/BoardControllerTest.php b/tests/unit/controller/BoardControllerTest.php
index fdb0ae203..357219907 100644
--- a/tests/unit/controller/BoardControllerTest.php
+++ b/tests/unit/controller/BoardControllerTest.php
@@ -24,6 +24,7 @@
 namespace OCA\Deck\Controller;
 
 use OCA\Deck\Db\Acl;
+use OCA\Deck\Db\Board;
 use OCP\IUser;
 
 class BoardControllerTest extends \Test\TestCase {
@@ -88,11 +89,12 @@ class BoardControllerTest extends \Test\TestCase {
 	}
 
 	public function testRead() {
+		$board = new Board();
 		$this->boardService->expects($this->once())
 			->method('find')
 			->with(123)
-			->willReturn(1);
-		$this->assertEquals(1, $this->controller->read(123));
+			->willReturn($board);
+		$this->assertEquals($board, $this->controller->read(123));
 	}
 
 	public function testCreate() {