Most of the posts highlight what I am focused on and express work and personal experience. Reason I put them here - recall later or help someone else with similar challenge.
ER's cards - cloud, virtualisation, UX/UI, automation
This tag gem is very old and has pretty decent user guide in its github page here.
ActsAsTaggableOn::Tag.joins("LEFT JOIN taggings on taggings.tag_id = tags.id").where("taggings.id is null").delete_all ActsAsTaggableOn::Tagging.joins("LEFT JOIN tags on tags.id = taggings.tag_id").where("tags.id is null").delete_all