diff --git a/Annotations/SyncEntity.php b/Annotations/SyncEntity.php
new file mode 100755
index 0000000..1786a19
--- /dev/null
+++ b/Annotations/SyncEntity.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace NTI\SyncBundle\Annotations;
+use Doctrine\Common\Annotations\Annotation\Required;
+
+/**
+ * Class SyncParent
+ * @package NTI\SyncBundle\Annotations
+ * @Annotation
+ */
+class SyncEntity {
+
+}
\ No newline at end of file
diff --git a/Entity/SyncFailedItemState.php b/Entity/SyncFailedItemState.php
old mode 100644
new mode 100755
index 7088247..4d4fcd9
--- a/Entity/SyncFailedItemState.php
+++ b/Entity/SyncFailedItemState.php
@@ -54,7 +54,7 @@ class SyncFailedItemState {
     /**
      * @var string
      *
-     * @ORM\Column(name="errors", columnDefinition="TEXT", length=65535, nullable=true)
+     * @ORM\Column(name="errors", type="text", nullable=true)
      */
     private $errors;
 
diff --git a/Entity/SyncMapping.php b/Entity/SyncMapping.php
old mode 100644
new mode 100755
index 04ac4d2..ab4ca91
--- a/Entity/SyncMapping.php
+++ b/Entity/SyncMapping.php
@@ -38,7 +38,7 @@ class SyncMapping
     /**
      * @var string
      *
-     * @ORM\Column(name="sync_service", type="string", length=255, nullable=false)
+     * @ORM\Column(name="sync_service", type="string", length=255, nullable=true)
      */
     private $syncService;
 
diff --git a/EventListener/DoctrineEventSubscriber.php b/EventListener/DoctrineEventSubscriber.php
deleted file mode 100755
index f9e3984..0000000
--- a/EventListener/DoctrineEventSubscriber.php
+++ /dev/null
@@ -1,84 +0,0 @@
-<?php
-
-namespace NTI\SyncBundle\EventListener;
-
-use AppBundle\Entity\Empanada\Empanada;
-use Doctrine\Common\Annotations\AnnotationReader;
-use Doctrine\Common\EventSubscriber;
-use Doctrine\ORM\EntityManagerInterface;
-use Doctrine\ORM\Event\LifecycleEventArgs;
-use Doctrine\ORM\Event\OnFlushEventArgs;
-use Doctrine\ORM\UnitOfWork;
-use NTI\SyncBundle\Annotations\SyncParent;
-use NTI\SyncBundle\Interfaces\SyncEntityInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
-
-class DoctrineEventSubscriber implements EventSubscriber
-{
-    private $container;
-    private $syncService;
-
-    public function __construct(ContainerInterface $container)
-    {
-        $this->container = $container;
-        $this->syncService = $this->container->get('nti.sync');
-    }
-
-    public function getSubscribedEvents()
-    {
-        return array(
-            'onFlush',
-            'preRemove',
-        );
-    }
-
-    public function onFlush(OnFlushEventArgs $args)
-    {
-
-        $em = $args->getEntityManager();
-        $uow = $em->getUnitOfWork();
-
-        foreach ($uow->getScheduledEntityUpdates() as $entity) {
-            // Check if the entity should be synchronized
-            if (!($entity instanceof SyncEntityInterface)) {
-                continue;
-            }
-            $this->processEntity($em, $entity);
-        }
-
-    }
-
-    public function preRemove(LifecycleEventArgs $args)
-    {
-
-    }
-
-    private function processEntity(EntityManagerInterface $em, $entity)
-    {
-        $uow = $em->getUnitOfWork();
-
-        $timestamp = time();
-
-        // Check if this class itself has a lastTimestamp
-        if(method_exists($entity, 'setLastTimestamp')) {
-            $entity->setLastTimestamp($timestamp);
-            $uow->computeChangeSet($em->getClassMetadata(get_class($entity)), $entity);
-        }
-
-        // Check if there are any relationships that should notified
-        $annotationReader = new AnnotationReader();
-        $reflection = new \ReflectionClass(get_class($entity));
-
-        /** @var \ReflectionProperty $property */
-        foreach ($reflection->getProperties() as $property) {
-            /** @var SyncParent $annotation */
-            if (null !== ($annotation = $annotationReader->getPropertyAnnotation($property, SyncParent::class))) {
-                $getter = $annotation->getter;
-                $parent = $entity->$getter();
-                if($parent instanceof SyncEntityInterface) {
-                    $this->processEntity($em, $parent);
-                }
-            }
-        }
-    }
-}
diff --git a/EventSubscriber/DoctrineEventSubscriber.php b/EventSubscriber/DoctrineEventSubscriber.php
new file mode 100755
index 0000000..0f58359
--- /dev/null
+++ b/EventSubscriber/DoctrineEventSubscriber.php
@@ -0,0 +1,125 @@
+<?php
+
+namespace NTI\SyncBundle\EventSubscriber;
+
+use Doctrine\Common\Annotations\AnnotationReader;
+use Doctrine\Common\EventSubscriber;
+use Doctrine\Common\Util\ClassUtils;
+use Doctrine\ORM\EntityManagerInterface;
+use Doctrine\ORM\Event\LifecycleEventArgs;
+use Doctrine\ORM\Event\OnFlushEventArgs;
+use Doctrine\ORM\PersistentCollection;
+use NTI\SyncBundle\Annotations\SyncEntity;
+use NTI\SyncBundle\Annotations\SyncParent;
+use NTI\SyncBundle\Entity\SyncMapping;
+use NTI\SyncBundle\Entity\SyncState;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+class DoctrineEventSubscriber implements EventSubscriber
+{
+    private $container;
+    private $syncService;
+
+    public function __construct(ContainerInterface $container)
+    {
+        $this->container = $container;
+        $this->syncService = $this->container->get('nti.sync');
+    }
+
+    public function getSubscribedEvents()
+    {
+        return array(
+            'onFlush',
+        );
+    }
+
+    public function onFlush(OnFlushEventArgs $args)
+    {
+
+        $em = $args->getEntityManager();
+        $uow = $em->getUnitOfWork();
+
+        foreach ($uow->getScheduledEntityUpdates() as $entity) {
+            $this->processEntity($em, $entity);
+        }
+
+        foreach ($uow->getScheduledEntityInsertions() as $entity) {
+            $this->processEntity($em, $entity);
+        }
+
+        foreach ($uow->getScheduledEntityDeletions() as $entity) {
+            $this->processEntity($em, $entity);
+            $this->container->get('nti.sync')->addToDeleteSyncState(ClassUtils::getClass($entity), $entity->getId());
+        }
+
+        /** @var PersistentCollection $collectionUpdate */
+        foreach ($uow->getScheduledCollectionUpdates() as $collectionUpdate) {
+            foreach($collectionUpdate as $entity) {
+                $this->processEntity($em, $entity);
+            }
+        }
+
+        /** @var PersistentCollection $collectionDeletion */
+        foreach($uow->getScheduledCollectionDeletions() as $collectionDeletion) {
+            foreach($collectionDeletion as $entity) {
+                $this->processEntity($em, $entity);
+                $this->container->get('nti.sync')->addToDeleteSyncState(ClassUtils::getClass($entity), $entity->getId());
+            }
+        }
+
+    }
+
+    private function processEntity(EntityManagerInterface $em, $entity)
+    {
+
+        $reflection = new \ReflectionClass(ClassUtils::getClass($entity));
+        $annotationReader = new AnnotationReader();
+        $syncEntityAnnotation = $annotationReader->getClassAnnotation($reflection, SyncEntity::class);
+        // Check if the entity should be synchronized
+        if (!$syncEntityAnnotation) {
+            return;
+        }
+
+        $uow = $em->getUnitOfWork();
+        $timestamp = time();
+
+        // Update the mapping's sync state if exists
+        $mapping = $em->getRepository(SyncMapping::class)->findOneBy(array("class" => get_class($entity)));
+        if($mapping) {
+            $syncState = $em->getRepository(SyncState::class)->findOneBy(array("mapping" => $mapping));
+            if(!$syncState) {
+                $syncState = new SyncState();
+                $syncState->setMapping($mapping);
+                $em->persist($syncState);
+            }
+            $syncState->setTimestamp($timestamp);
+            $uow->recomputeSingleEntityChangeSet($em->getClassMetadata(SyncState::class), $syncState);
+        }
+
+        // Check if this class itself has a lastTimestamp
+        if(method_exists($entity, 'setLastTimestamp')) {
+            $entity->setLastTimestamp($timestamp);
+            $uow->recomputeSingleEntityChangeSet($em->getClassMetadata(get_class($entity)), $entity);
+        }
+
+        // Notify relationships
+        /** @var \ReflectionProperty $property */
+        foreach ($reflection->getProperties() as $property) {
+
+            /** @var SyncParent $annotation */
+            if (null !== ($annotation = $annotationReader->getPropertyAnnotation($property, SyncParent::class))) {
+                $getter = $annotation->getter;
+                $parent = $entity->$getter();
+                dump($parent);
+                die;
+                // Using ClassUtils as $parent is actually a Proxy of the class
+                $reflrectionParent = new \ReflectionClass(ClassUtils::getClass($parent));
+                $syncParentAnnotation = $annotationReader->getClassAnnotation($reflrectionParent, SyncEntity::class);
+                if(!$syncParentAnnotation) {
+                    continue;
+                }
+                $this->processEntity($em, $parent);
+            }
+        }
+    }
+}
diff --git a/Interfaces/SyncEntityInterface.php b/Interfaces/SyncEntityInterface.php
deleted file mode 100755
index 3b54861..0000000
--- a/Interfaces/SyncEntityInterface.php
+++ /dev/null
@@ -1,6 +0,0 @@
-<?php
-
-namespace NTI\SyncBundle\Interfaces;
-
-interface SyncEntityInterface {
-}
\ No newline at end of file
diff --git a/Resources/config/services.yml b/Resources/config/services.yml
index 212e162..e065d6d 100755
--- a/Resources/config/services.yml
+++ b/Resources/config/services.yml
@@ -1,6 +1,6 @@
 services:
     nti.sync.doctrine.listener:
-        class: NTI\SyncBundle\EventListener\DoctrineEventSubscriber
+        class: NTI\SyncBundle\EventSubscriber\DoctrineEventSubscriber
         arguments: ["@service_container"]
         tags:
             - { name: doctrine.event_subscriber, connection: default }
diff --git a/Service/SyncService.php b/Service/SyncService.php
index 54a3b1d..7a7129e 100755
--- a/Service/SyncService.php
+++ b/Service/SyncService.php
@@ -5,6 +5,7 @@
 use Doctrine\ORM\EntityManager;
 use Doctrine\ORM\EntityManagerInterface;
 use NTI\SyncBundle\Entity\SyncDeleteState;
+use NTI\SyncBundle\Entity\SyncFailedItemState;
 use NTI\SyncBundle\Entity\SyncMapping;
 use NTI\SyncBundle\Entity\SyncNewItemState;
 use NTI\SyncBundle\Entity\SyncState;
@@ -62,10 +63,7 @@ public function getFromMappings($mappings) {
 
             $deletes = $this->em->getRepository(SyncDeleteState::class)->findFromTimestamp($mappingName, $timestamp);
             $newItems = $this->em->getRepository(SyncNewItemState::class)->findFromTimestampAndMapping($mappingName, $timestamp);
-	    /**
-             * Failed Items Synchronization
-             */
-            $failedItems = $this->em->getRepository('NTISyncBundle:SyncFailedItemState')->findFromTimestampAndMapping($mappingName, $timestamp);
+            $failedItems = $this->em->getRepository(SyncFailedItemState::class)->findFromTimestampAndMapping($mappingName, $timestamp);
 
             /** @var SyncRepositoryInterface $repository */
             $repository = $this->em->getRepository($syncMapping->getClass());
@@ -88,30 +86,6 @@ public function getFromMappings($mappings) {
         return $changes;
     }
 
-    public function updateSyncState(EntityManagerInterface $em, $class, $timestamp) {
-
-        $mapping = $em->getRepository(SyncMapping::class)->findOneBy(array("class" => $class));
-        if(!$mapping) {
-            return;
-        }
-
-        $syncState = $em->getRepository(SyncState::class)->findOneBy(array("mapping" => $mapping));
-
-        $uow = $em->getUnitOfWork();
-
-        if(!$syncState) {
-            $syncState = new SyncState();
-            $syncState->setMapping($mapping);
-            $syncState->setTimestamp($timestamp);
-            $em->persist($syncState);
-            $uow->computeChangeSet($em->getClassMetadata(SyncState::class), $syncState);
-        } else {
-            $syncState->setTimestamp($timestamp);
-            $uow->recomputeSingleEntityChangeSet($em->getClassMetadata(SyncState::class), $syncState);
-        }
-
-    }
-
     /**
      * Create a new SyncDeleteState for the given class/id
      *
@@ -122,6 +96,7 @@ public function addToDeleteSyncState($class, $id) {
 
         $this->em = $this->container->get('doctrine')->getManager();
 
+        /** @var SyncMapping $mapping */
         $mapping = $this->em->getRepository(SyncMapping::class)->findOneBy(array("class" => $class));
         if(!$mapping) {
             return;
@@ -133,12 +108,5 @@ public function addToDeleteSyncState($class, $id) {
         $deleteEntry->setTimestamp(time());
 
         $this->em->persist($deleteEntry);
-
-        try {
-            $this->em->flush();
-        } catch (\Exception $ex) {
-            error_log("Unable to register deletion of object: " . $class . " with ID " . $id);
-            error_log($ex->getMessage());
-        }
     }
 }