Change record status: 
Project: 
Introduced in branch: 
8.0.x
Introduced in version: 
8.0.0-beta12
Description: 

node_last_changed() got removed, but there are still methods on NodeInterface() you can use:

Before

$changed_time = node_last_changed($node->id());

After

$node = \Drupal::entityManager()->getStorage('node')->loadUnchanged($nid);
$changed_time = $node->getChangedTimeAcrossTranslations();
Impacts: 
Module developers