Joomla! 3.9 will be a GDPR release. Which will mean the new Joomla! 4 compatibility layer will be Joomla! 3.10. Since GDPR is the word on everyones lips at the moment this is really important. For more information check out this official Joomla! announcement https://www.joomla.org/announcements/release-news/5731-joomla-3-9-and-joomla-3-10.html
In our last meeting we discussed an extension which looks pretty sweet too. If you're interested, check it out here: https://extensions.joomla.org/extensions/extension/site-management/cookie-control/gdpr/
You might also find this article useful https://magazine.joomla.org/issues/issue-apr-2018/item/3318-privacy-by-default-and-gdpr-examples-and-best-practises
Hands up if you love GDPR?