diff --git a/core/modules/menu_ui/menu_ui.module b/core/modules/menu_ui/menu_ui.module
index cfd29f0..d5e4520 100644
--- a/core/modules/menu_ui/menu_ui.module
+++ b/core/modules/menu_ui/menu_ui.module
@@ -127,54 +127,33 @@ function menu_ui_block_view_system_menu_block_alter(array &$build, BlockPluginIn
 }
 
 /**
- * Implements hook_ENTITY_TYPE_insert() for node entities.
+ * Helper function to save a menu link for a node.
  */
-function menu_ui_node_insert(EntityInterface $node) {
-  menu_ui_node_save($node);
-}
-
-/**
- * Implements hook_ENTITY_TYPE_update() for node entities.
- */
-function menu_ui_node_update(EntityInterface $node) {
-  menu_ui_node_save($node);
-}
-
-/**
- * Helper for hook_ENTITY_TYPE_insert() and hook_ENTITY_TYPE_update() for nodes.
- */
-function menu_ui_node_save(EntityInterface $node) {
-  if (!empty($node->menu)) {
-    /** @var \Drupal\menu_link_content\MenuLinkContentInterface $entity */
-    $definition = $node->menu;
-    if (trim($definition['title'])) {
-      if (!empty($definition['entity_id'])) {
-        $entity = MenuLinkContent::load($definition['entity_id']);
-        $entity->enabled->value = 1;
-        $entity->title->value = trim($definition['title']);
-        $entity->description->value = trim($definition['description']);
-        $entity->menu_name->value = $definition['menu_name'];
-        $entity->parent->value = $definition['parent'];
-        $entity->weight->value = isset($definition['weight']) ? $definition['weight'] : 0;
-      }
-      else {
-        // Create a new menu_link_content entity.
-        $entity = entity_create('menu_link_content', array(
-          'title' => trim($definition['title']),
-          'description' => trim($definition['description']),
-          'link' => ['uri' => 'entity:node/' . $node->id()],
-          'menu_name' => $definition['menu_name'],
-          'parent' => $definition['parent'],
-          'weight' => isset($definition['weight']) ? $definition['weight'] : 0,
-          'enabled' => 1,
-          'langcode' => $node->getUntranslated()->language()->getId(),
-        ));
-      }
-      if (!$entity->save()) {
-        drupal_set_message(t('There was an error saving the menu link.'), 'error');
-      }
-    }
+function menu_ui_node_save(NodeInterface $node, array $definition) {
+  /** @var \Drupal\menu_link_content\MenuLinkContentInterface $entity */
+  if (!empty($definition['entity_id'])) {
+    $entity = MenuLinkContent::load($definition['entity_id']);
+    $entity->enabled->value = 1;
+    $entity->title->value = trim($definition['title']);
+    $entity->description->value = trim($definition['description']);
+    $entity->menu_name->value = $definition['menu_name'];
+    $entity->parent->value = $definition['parent'];
+    $entity->weight->value = isset($definition['weight']) ? $definition['weight'] : 0;
+  }
+  else {
+    // Create a new menu_link_content entity.
+    $entity = entity_create('menu_link_content', array(
+      'title' => trim($definition['title']),
+      'description' => trim($definition['description']),
+      'link' => ['uri' => 'entity:node/' . $node->id()],
+      'menu_name' => $definition['menu_name'],
+      'parent' => $definition['parent'],
+      'weight' => isset($definition['weight']) ? $definition['weight'] : 0,
+      'enabled' => 1,
+      'langcode' => $node->getUntranslated()->language()->getId(),
+    ));
   }
+  $entity->save();
 }
 
 /**
@@ -196,70 +175,73 @@ function menu_ui_node_predelete(EntityInterface $node) {
 }
 
 /**
- * Implements hook_node_prepare_form().
+ * Returns the definition for a menu link for the given node.
+ *
+ * @param \Drupal\node\NodeInterface $node
+ *   The node entity.
+ *
+ * @return array
+ *   A definition array that matches the form structure.
  */
-function menu_ui_node_prepare_form(NodeInterface $node, $operation, FormStateInterface $form_state) {
-  if (!$form_state->get('menu_link_definition')) {
-    // Prepare the node for the edit form so that $node->menu always exists.
-    /** @var \Drupal\node\NodeTypeInterface $node_type */
-    $node_type = $node->type->entity;
-    $menu_name = strtok($node_type->getThirdPartySetting('menu_ui', 'parent', 'main:'), ':');
-    $definition = FALSE;
-    if ($node->id()) {
-      $id = FALSE;
-      // Give priority to the default menu
-      $type_menus = $node_type->getThirdPartySetting('menu_ui', 'available_menus', array('main'));
-      if (in_array($menu_name, $type_menus)) {
-        $query = \Drupal::entityQuery('menu_link_content')
-          // @todo Use link.uri once https://www.drupal.org/node/2391217 is in.
-          ->condition('link__uri', 'node/' . $node->id())
-          ->condition('menu_name', $menu_name)
-          ->sort('id', 'ASC')
-          ->range(0, 1);
-        $result = $query->execute();
+function menu_ui_get_definition(NodeInterface $node) {
+  // Prepare the definition for the edit form.
+  /** @var \Drupal\node\NodeTypeInterface $node_type */
+  $node_type = $node->type->entity;
+  $menu_name = strtok($node_type->getThirdPartySetting('menu_ui', 'parent', 'main:'), ':');
+  $definition = FALSE;
+  if ($node->id()) {
+    $id = FALSE;
+    // Give priority to the default menu
+    $type_menus = $node_type->getThirdPartySetting('menu_ui', 'available_menus', array('main'));
+    if (in_array($menu_name, $type_menus)) {
+      $query = \Drupal::entityQuery('menu_link_content')
+        // @todo Use link.uri once https://www.drupal.org/node/2391217 is in.
+        ->condition('link__uri', 'node/' . $node->id())
+        ->condition('menu_name', $menu_name)
+        ->sort('id', 'ASC')
+        ->range(0, 1);
+      $result = $query->execute();
 
-        $id = (!empty($result)) ? reset($result) : FALSE;
-      }
-      // Check all allowed menus if a link does not exist in the default menu.
-      if (!$id && !empty($type_menus)) {
-        $query = \Drupal::entityQuery('menu_link_content')
-          // @todo Use link.uri once https://www.drupal.org/node/2391217 is in.
-          ->condition('link__uri', 'entity:node/' . $node->id())
-          ->condition('menu_name', array_values($type_menus), 'IN')
-          ->sort('id', 'ASC')
-          ->range(0, 1);
-        $result = $query->execute();
-
-        $id = (!empty($result)) ? reset($result) : FALSE;
-      }
-      if ($id) {
-        $menu_link = MenuLinkContent::load($id);
-        $definition = array(
-          'entity_id' => $menu_link->id(),
-          'id' => $menu_link->getPluginId(),
-          'title' => $menu_link->getTitle(),
-          'description' => $menu_link->getDescription(),
-          'menu_name' => $menu_link->getMenuName(),
-          'parent' => $menu_link->getParentId(),
-          'weight' => $menu_link->getWeight(),
-        );
-      }
+      $id = (!empty($result)) ? reset($result) : FALSE;
     }
+    // Check all allowed menus if a link does not exist in the default menu.
+    if (!$id && !empty($type_menus)) {
+      $query = \Drupal::entityQuery('menu_link_content')
+        // @todo Use link.uri once https://www.drupal.org/node/2391217 is in.
+        ->condition('link__uri', 'entity:node/' . $node->id())
+        ->condition('menu_name', array_values($type_menus), 'IN')
+        ->sort('id', 'ASC')
+        ->range(0, 1);
+      $result = $query->execute();
 
-    if (!$definition) {
+      $id = (!empty($result)) ? reset($result) : FALSE;
+    }
+    if ($id) {
+      $menu_link = MenuLinkContent::load($id);
       $definition = array(
-        'entity_id' => 0,
-        'id' => '',
-        'title' => '',
-        'description' => '',
-        'menu_name' => $menu_name,
-        'parent' => '',
-        'weight' => 0,
+        'entity_id' => $menu_link->id(),
+        'id' => $menu_link->getPluginId(),
+        'title' => $menu_link->getTitle(),
+        'description' => $menu_link->getDescription(),
+        'menu_name' => $menu_link->getMenuName(),
+        'parent' => $menu_link->getParentId(),
+        'weight' => $menu_link->getWeight(),
       );
     }
-    // Set default values.
-    $form_state->set('menu_link_definition', $definition);
   }
+
+  if (!$definition) {
+    $definition = array(
+      'entity_id' => 0,
+      'id' => '',
+      'title' => '',
+      'description' => '',
+      'menu_name' => $menu_name,
+      'parent' => '',
+      'weight' => 0,
+    );
+  }
+  return $definition;
 }
 
 /**
@@ -267,13 +249,13 @@ function menu_ui_node_prepare_form(NodeInterface $node, $operation, FormStateInt
  *
  * Adds menu item fields to the node form.
  *
- * @see menu_ui_node_submit()
+ * @see menu_ui_form_node_form_submit()
  */
 function menu_ui_form_node_form_alter(&$form, FormStateInterface $form_state) {
   // Generate a list of possible parents (not including this link or descendants).
   // @todo This must be handled in a #process handler.
   $node = $form_state->getFormObject()->getEntity();
-  $definition = $form_state->get('menu_link_definition');
+  $definition = menu_ui_get_definition($node);
   /** @var \Drupal\node\NodeTypeInterface $node_type */
   $node_type = $node->type->entity;
   /** @var \Drupal\Core\Menu\MenuParentFormSelectorInterface $menu_parent_selector */
@@ -353,14 +335,16 @@ function menu_ui_form_node_form_alter(&$form, FormStateInterface $form_state) {
     '#default_value' => $definition['weight'],
     '#description' => t('Menu links with lower weights are displayed before links with higher weights.'),
   );
+  $form['actions']['submit']['#submit'][] = 'menu_ui_form_node_form_submit';
 }
 
 /**
- * Implements hook_node_submit().
+ * Form submission handler for menu item field on the node form.
  *
  * @see menu_ui_form_node_form_alter()
  */
-function menu_ui_node_submit(EntityInterface $node, $form, FormStateInterface $form_state) {
+function menu_ui_form_node_form_submit($form, FormStateInterface $form_state) {
+  $node = $form_state->getFormObject()->getEntity();
   if (!$form_state->isValueEmpty('menu')) {
     $definition = $form_state->getValue('menu');
     if (empty($definition['enabled'])) {
@@ -377,11 +361,7 @@ function menu_ui_node_submit(EntityInterface $node, $form, FormStateInterface $f
         $definition['menu_name'] = $menu_name;
         $definition['parent'] = $parent;
       }
-      // @todo Figure out how to save this data without adding non-Field API
-      //   properties to the node entity. https://www.drupal.org/node/2310173
-      //   We have to tack this onto the node so we can save it later when we
-      //   have a node ID for any new node.
-      $node->menu = $definition;
+      menu_ui_node_save($node, $definition);
     }
   }
 }
diff --git a/core/modules/node/node.api.php b/core/modules/node/node.api.php
index 9ae46d6..f04de79 100644
--- a/core/modules/node/node.api.php
+++ b/core/modules/node/node.api.php
@@ -409,65 +409,6 @@ function hook_node_update_index(\Drupal\node\NodeInterface $node, $langcode) {
 }
 
 /**
- * Perform node validation before a node is created or updated.
- *
- * This hook is invoked from NodeForm::validate(), after a user has
- * finished editing the node and is previewing or submitting it. It is invoked
- * at the end of all the standard validation steps.
- *
- * To indicate a validation error, use $form_state->setErrorByName().
- *
- * Note: Changes made to the $node object within your hook implementation will
- * have no effect.  The preferred method to change a node's content is to use
- * hook_node_presave() instead. If it is really necessary to change the node at
- * the validate stage, you can use setValueForElement().
- *
- * @param \Drupal\node\NodeInterface $node
- *   The node being validated.
- * @param $form
- *   The form being used to edit the node.
- * @param $form_state
- *   The current state of the form.
- *
- * @ingroup entity_crud
- */
-function hook_node_validate(\Drupal\node\NodeInterface $node, $form, \Drupal\Core\Form\FormStateInterface $form_state) {
-  if (isset($node->end) && isset($node->start)) {
-    if ($node->start > $node->end) {
-      $form_state->setErrorByName('time', t('An event may not end before it starts.'));
-    }
-  }
-}
-
-/**
- * Act on a node after validated form values have been copied to it.
- *
- * This hook is invoked when a node form is submitted with either the "Save" or
- * "Preview" button, after form values have been copied to the form state's node
- * object, but before the node is saved or previewed. It is a chance for modules
- * to adjust the node's properties from what they are simply after a copy from
- * $form_state->getValues(). This hook is intended for adjusting non-field-related
- * properties.
- *
- * @param \Drupal\node\NodeInterface $node
- *   The node entity being updated in response to a form submission.
- * @param $form
- *   The form being used to edit the node.
- * @param $form_state
- *   The current state of the form.
- *
- * @ingroup entity_crud
- */
-function hook_node_submit(\Drupal\node\NodeInterface $node, $form, \Drupal\Core\Form\FormStateInterface $form_state) {
-  // Decompose the selected menu parent option into 'menu_name' and 'parent', if
-  // the form used the default parent selection widget.
-  $parent = $form_state->getValue(array('menu', 'parent'));
-  if (!empty($parent)) {
-    list($node->menu['menu_name'], $node->menu['parent']) = explode(':', $parent);
-  }
-}
-
-/**
  * Provide additional methods of scoring for core search results for nodes.
  *
  * A node's search score is used to rank it among other nodes matched by the
diff --git a/core/modules/node/src/NodeForm.php b/core/modules/node/src/NodeForm.php
index fb8daa9..fda9fdb 100644
--- a/core/modules/node/src/NodeForm.php
+++ b/core/modules/node/src/NodeForm.php
@@ -293,14 +293,6 @@ public function validate(array $form, FormStateInterface $form_state) {
       $form_state->setErrorByName('changed', $this->t('The content on this page has either been modified by another user, or you have already submitted modifications using this form. As a result, your changes cannot be saved.'));
     }
 
-    // Invoke hook_node_validate() for validation needed by modules.
-    // Can't use \Drupal::moduleHandler()->invokeAll(), because $form_state must
-    // be receivable by reference.
-    foreach (\Drupal::moduleHandler()->getImplementations('node_validate') as $module) {
-      $function = $module . '_node_validate';
-      $function($node, $form, $form_state);
-    }
-
     parent::validate($form, $form_state);
   }
 
@@ -328,12 +320,6 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
     else {
       $node->setNewRevision(FALSE);
     }
-
-    $node->validated = TRUE;
-    foreach (\Drupal::moduleHandler()->getImplementations('node_submit') as $module) {
-      $function = $module . '_node_submit';
-      $function($node, $form, $form_state);
-    }
   }
 
   /**
diff --git a/core/modules/node/src/Tests/NodeSaveTest.php b/core/modules/node/src/Tests/NodeSaveTest.php
index 068eaae..b850cb4 100644
--- a/core/modules/node/src/Tests/NodeSaveTest.php
+++ b/core/modules/node/src/Tests/NodeSaveTest.php
@@ -63,8 +63,7 @@ function testImport() {
     $node = entity_create('node', $node);
     $node->enforceIsNew();
 
-    // Verify that node_submit did not overwrite the user ID.
-    $this->assertEqual($node->getOwnerId(), $this->webUser->id(), 'Function node_submit() preserves user ID');
+    $this->assertEqual($node->getOwnerId(), $this->webUser->id());
 
     $node->save();
     // Test the import.
diff --git a/core/modules/system/entity.api.php b/core/modules/system/entity.api.php
index ed04686..de42abd 100644
--- a/core/modules/system/entity.api.php
+++ b/core/modules/system/entity.api.php
@@ -152,7 +152,6 @@
  *
  * Some specific entity types have additional hooks that are run during
  * various steps in the process:
- * - Node entities: hook_node_validate() and hook_submit().
  *
  * @section delete Delete operations
  * To delete one or more entities, load them and then delete them: