Crowd Sync

I have been working a project which involved syncing users between Drupal and Crowd. There were multiple Drupal sites which users access and update their credentials. When a user changes his account info in one Drupal site, it is supposed to be synced with Crowd and then propagated onto other Drupal sites as well. (in case the connection with crowd fails)

I have built the code based on Crowd Extended Rest Methods. I have tried to put the code as generic as possible only syncing the native Crowd profile fields . The users are updated into crowd using hook_user_presave() and then synced onto other Drupal sites using hook_cron(), queues. The module also works when registration is set only on validation of email which was not possible before. All the user sync in a particular site happens based on groups <-> roles mapping of Crowd module. The module also has a batch process to sync users where this module is installed in an already running website with users.