diff --git a/app/models/collection.rb b/app/models/collection.rb
index ee86df8dc..3c9e4696c 100644
--- a/app/models/collection.rb
+++ b/app/models/collection.rb
@@ -4,7 +4,6 @@ class Collection < ApplicationRecord
   belongs_to :user
   belongs_to :organization, optional: true
 
-  validates :user_id, presence: true
   validates :slug, presence: true, uniqueness: { scope: :user_id }
 
   after_touch :touch_articles
diff --git a/app/models/discussion_lock.rb b/app/models/discussion_lock.rb
index 96d39b01a..2e3f815bc 100644
--- a/app/models/discussion_lock.rb
+++ b/app/models/discussion_lock.rb
@@ -11,6 +11,5 @@ class DiscussionLock < ApplicationRecord
 
   include StringAttributeCleaner.for(:notes, :reason)
 
-  validates :article_id, presence: true, uniqueness: true
-  validates :locking_user_id, presence: true
+  validates :article_id, uniqueness: true
 end
diff --git a/app/models/follow.rb b/app/models/follow.rb
index 28d56ceac..6f0894104 100644
--- a/app/models/follow.rb
+++ b/app/models/follow.rb
@@ -33,9 +33,7 @@ class Follow < ApplicationRecord
   after_save :touch_follower
 
   validates :blocked, inclusion: { in: [true, false] }
-  validates :followable_id, presence: true
   validates :followable_type, presence: true
-  validates :follower_id, presence: true
   validates :follower_type, presence: true
   validates :subscription_status, presence: true, inclusion: { in: %w[all_articles none] }
 
diff --git a/app/models/html_variant_success.rb b/app/models/html_variant_success.rb
index c074107a2..93b55353c 100644
--- a/app/models/html_variant_success.rb
+++ b/app/models/html_variant_success.rb
@@ -1,6 +1,4 @@
 class HtmlVariantSuccess < ApplicationRecord
   belongs_to :html_variant
   belongs_to :article, optional: true
-
-  validates :html_variant_id, presence: true
 end
diff --git a/app/models/html_variant_trial.rb b/app/models/html_variant_trial.rb
index 9872d142b..468a0530e 100644
--- a/app/models/html_variant_trial.rb
+++ b/app/models/html_variant_trial.rb
@@ -1,6 +1,4 @@
 class HtmlVariantTrial < ApplicationRecord
   belongs_to :html_variant
   belongs_to :article, optional: true
-
-  validates :html_variant_id, presence: true
 end
diff --git a/app/models/identity.rb b/app/models/identity.rb
index f6663e631..055aea7db 100644
--- a/app/models/identity.rb
+++ b/app/models/identity.rb
@@ -18,7 +18,6 @@ class Identity < ApplicationRecord
   validates :uid, uniqueness: { scope: :provider }, if: proc { |identity|
                                                           identity.uid_changed? || identity.provider_changed?
                                                         }
-  validates :user_id, presence: true
   validates :user_id, uniqueness: { scope: :provider }, if: proc { |identity|
                                                               identity.user_id_changed? || identity.provider_changed?
                                                             }
diff --git a/app/models/listing.rb b/app/models/listing.rb
index a7f2b6de7..2b81eef90 100644
--- a/app/models/listing.rb
+++ b/app/models/listing.rb
@@ -19,7 +19,6 @@ class Listing < ApplicationRecord
   acts_as_taggable_on :tags
   has_many :credits, as: :purchase, inverse_of: :purchase, dependent: :nullify
 
-  validates :user_id, presence: true
   validates :organization_id, presence: true, unless: :user_id?
 
   validates :title, presence: true, length: { maximum: 128 }
diff --git a/app/models/mention.rb b/app/models/mention.rb
index 0db414f1c..08813eae2 100644
--- a/app/models/mention.rb
+++ b/app/models/mention.rb
@@ -9,8 +9,7 @@ class Mention < ApplicationRecord
   belongs_to :user
   belongs_to :mentionable, polymorphic: true
 
-  validates :user_id, presence: true, uniqueness: { scope: %i[mentionable_id mentionable_type] }
-  validates :mentionable_id, presence: true
+  validates :user_id, uniqueness: { scope: %i[mentionable_id mentionable_type] }
   validates :mentionable_type, presence: true
   validate :permission
 
diff --git a/app/models/notification_subscription.rb b/app/models/notification_subscription.rb
index ba5db5ee9..ff58f0ee8 100644
--- a/app/models/notification_subscription.rb
+++ b/app/models/notification_subscription.rb
@@ -10,11 +10,13 @@ class NotificationSubscription < ApplicationRecord
   belongs_to :user
 
   validates :config, presence: true, inclusion: { in: %w[all_comments top_level_comments only_author_comments] }
-  validates :notifiable_id, presence: true
   validates :notifiable_type, presence: true, inclusion: { in: %w[Comment Article] }
   validates :user_id, uniqueness: { scope: %i[notifiable_type notifiable_id] }
 
   class << self
+    # @param notifiable [Comment, Article]
+    #
+    # @see notifiable_type's validation
     def update_notification_subscriptions(notifiable)
       NotificationSubscriptions::UpdateWorker.perform_async(
         notifiable.id,
diff --git a/app/models/organization_membership.rb b/app/models/organization_membership.rb
index 0729b7e65..a0ba6055a 100644
--- a/app/models/organization_membership.rb
+++ b/app/models/organization_membership.rb
@@ -7,7 +7,7 @@ class OrganizationMembership < ApplicationRecord
 
   USER_TYPES = %w[admin member guest].freeze
 
-  validates :user_id, :organization_id, :type_of_user, presence: true
+  validates :type_of_user, presence: true
   validates :user_id, uniqueness: { scope: :organization_id }
   validates :type_of_user, inclusion: { in: USER_TYPES }
 
diff --git a/app/models/podcast_episode_appearance.rb b/app/models/podcast_episode_appearance.rb
index 3f8fe7e34..7c4d6f5ac 100644
--- a/app/models/podcast_episode_appearance.rb
+++ b/app/models/podcast_episode_appearance.rb
@@ -5,6 +5,6 @@ class PodcastEpisodeAppearance < ApplicationRecord
   belongs_to :user, class_name: "User", inverse_of: :podcast_episode_appearances
   belongs_to :podcast_episode
   validates :podcast_episode_id, uniqueness: { scope: :user_id }
-  validates :podcast_episode_id, :user_id, :role, presence: true
+  validates :role, presence: true
   validates :role, inclusion: { in: %w[host guest], message: "provided role is not valid" }
 end
diff --git a/app/models/podcast_ownership.rb b/app/models/podcast_ownership.rb
index 6e51e75ae..9bb6b6bfa 100644
--- a/app/models/podcast_ownership.rb
+++ b/app/models/podcast_ownership.rb
@@ -6,5 +6,4 @@ class PodcastOwnership < ApplicationRecord
   belongs_to :podcast
 
   validates :podcast_id, uniqueness: { scope: :user_id }
-  validates :podcast_id, :user_id, presence: true
 end
diff --git a/app/models/poll_vote.rb b/app/models/poll_vote.rb
index 5d381795f..58ad0a1da 100644
--- a/app/models/poll_vote.rb
+++ b/app/models/poll_vote.rb
@@ -14,9 +14,9 @@ class PollVote < ApplicationRecord
   counter_culture :poll
 
   # In the future we'll remove this constraint if/when we allow multi-answer polls
-  validates :poll_id, presence: true, uniqueness: { scope: :user_id }
+  validates :poll_id, uniqueness: { scope: :user_id }
 
-  validates :poll_option_id, presence: true, uniqueness: { scope: :user_id }
+  validates :poll_option_id, uniqueness: { scope: :user_id }
   validate :one_vote_per_poll_per_user
 
   after_destroy :touch_poll_votes_count
diff --git a/app/models/profile_pin.rb b/app/models/profile_pin.rb
index e39fbb578..8312dc61b 100644
--- a/app/models/profile_pin.rb
+++ b/app/models/profile_pin.rb
@@ -5,9 +5,8 @@ class ProfilePin < ApplicationRecord
   belongs_to :pinnable, polymorphic: true
   belongs_to :profile, polymorphic: true
 
-  validates :profile_id, presence: true
   validates :profile_type, inclusion: { in: %w[User] } # Future could be organization, tag, etc.
-  validates :pinnable_id, presence: true, uniqueness: { scope: %i[profile_id profile_type pinnable_type] }
+  validates :pinnable_id, uniqueness: { scope: %i[profile_id profile_type pinnable_type] }
   validates :pinnable_type, inclusion: { in: %w[Article] } # Future could be comments, etc.
   validate :only_five_pins_per_profile, on: :create
   validate :pinnable_belongs_to_profile
diff --git a/app/models/sponsorship.rb b/app/models/sponsorship.rb
index 337f47e9e..976d5977c 100644
--- a/app/models/sponsorship.rb
+++ b/app/models/sponsorship.rb
@@ -19,7 +19,7 @@ class Sponsorship < ApplicationRecord
   validates :level, presence: true, inclusion: { in: LEVELS }
   validates :status, presence: true, inclusion: { in: STATUSES }
   validates :url, url: { allow_blank: true, no_local: true, schemes: %w[http https] }
-  validates :user, :organization, :featured_number, presence: true
+  validates :featured_number, presence: true
   validates :sponsorable_type, inclusion: {
     in: SPONSORABLE_TYPES,
     allow_blank: true,
diff --git a/app/models/tag_adjustment.rb b/app/models/tag_adjustment.rb
index 5e8981e98..9b18bfcc4 100644
--- a/app/models/tag_adjustment.rb
+++ b/app/models/tag_adjustment.rb
@@ -1,7 +1,4 @@
 class TagAdjustment < ApplicationRecord
-  validates :user_id, presence: true
-  validates :article_id, presence: true
-  validates :tag_id, presence: true
   validates :tag_name, presence: true, uniqueness: { scope: :article_id, message: "can't be an already adjusted tag" }
   validates :reason_for_adjustment, presence: true
   validates :adjustment_type, inclusion: { in: %w[removal addition] }, presence: true
diff --git a/app/models/user_block.rb b/app/models/user_block.rb
index f7df8b781..d11f467a8 100644
--- a/app/models/user_block.rb
+++ b/app/models/user_block.rb
@@ -2,7 +2,7 @@ class UserBlock < ApplicationRecord
   belongs_to :blocker, class_name: "User", inverse_of: :blocker_blocks
   belongs_to :blocked, class_name: "User", inverse_of: :blocked_blocks
 
-  validates :blocked_id, :blocker_id, :config, presence: true
+  validates :config, presence: true
   validates :blocked_id, uniqueness: { scope: %i[blocker_id] }
   validates :config, inclusion: { in: %w[default] }
   validate :blocker_cannot_be_same_as_blocked
diff --git a/app/models/user_subscription.rb b/app/models/user_subscription.rb
index 42cbab1b6..6e025e36f 100644
--- a/app/models/user_subscription.rb
+++ b/app/models/user_subscription.rb
@@ -11,10 +11,8 @@ class UserSubscription < ApplicationRecord
   belongs_to :subscriber, class_name: "User", inverse_of: :subscribed_to_user_subscriptions
   belongs_to :user_subscription_sourceable, polymorphic: true, optional: true
 
-  validates :author_id, presence: true
-
   validates :subscriber_email, presence: true
-  validates :subscriber_id, presence: true, uniqueness: {
+  validates :subscriber_id, uniqueness: {
     scope: %i[subscriber_email user_subscription_sourceable_type user_subscription_sourceable_id]
   }
 
diff --git a/app/models/users/setting.rb b/app/models/users/setting.rb
index 1cae82e85..91a7174b5 100644
--- a/app/models/users/setting.rb
+++ b/app/models/users/setting.rb
@@ -24,7 +24,6 @@ module Users
               :brand_color2,
               format: { with: HEX_COLOR_REGEXP, message: "is not a valid hex color" },
               allow_nil: true
-    validates :user_id, presence: true
     validates :experience_level, numericality: { less_than_or_equal_to: 10 }, allow_blank: true
     validates :feed_referential_link, inclusion: { in: [true, false] }
     validates :feed_url, length: { maximum: 500 }, allow_nil: true
diff --git a/spec/models/collection_spec.rb b/spec/models/collection_spec.rb
index 449cf8b38..7f04348a8 100644
--- a/spec/models/collection_spec.rb
+++ b/spec/models/collection_spec.rb
@@ -9,7 +9,6 @@ RSpec.describe Collection, type: :model do
     it { is_expected.to belong_to(:organization).optional }
     it { is_expected.to have_many(:articles).dependent(:nullify) }
 
-    it { is_expected.to validate_presence_of(:user_id) }
     it { is_expected.to validate_presence_of(:slug) }
     it { is_expected.to validate_uniqueness_of(:slug).scoped_to(:user_id) }
   end
diff --git a/spec/models/discussion_lock_spec.rb b/spec/models/discussion_lock_spec.rb
index 38bfbb27d..71fe1a264 100644
--- a/spec/models/discussion_lock_spec.rb
+++ b/spec/models/discussion_lock_spec.rb
@@ -11,8 +11,6 @@ RSpec.describe DiscussionLock, type: :model do
   describe "validations" do
     subject { discussion_lock }
 
-    it { is_expected.to validate_presence_of(:article_id) }
-    it { is_expected.to validate_presence_of(:locking_user_id) }
     it { is_expected.to validate_uniqueness_of(:article_id) }
 
     it "sanitizes attributes before validation", :aggregate_failures do
diff --git a/spec/models/follow_spec.rb b/spec/models/follow_spec.rb
index 78709c331..f7e7dbdfc 100644
--- a/spec/models/follow_spec.rb
+++ b/spec/models/follow_spec.rb
@@ -9,9 +9,7 @@ RSpec.describe Follow, type: :model do
     subject { user.follow(user_2) }
 
     it { is_expected.to validate_inclusion_of(:subscription_status).in_array(%w[all_articles none]) }
-    it { is_expected.to validate_presence_of(:followable_id) }
     it { is_expected.to validate_presence_of(:followable_type) }
-    it { is_expected.to validate_presence_of(:follower_id) }
     it { is_expected.to validate_presence_of(:follower_type) }
     it { is_expected.to validate_presence_of(:subscription_status) }
   end
diff --git a/spec/models/github_repo_spec.rb b/spec/models/github_repo_spec.rb
index 25b1dbf3b..c69d4d7c4 100644
--- a/spec/models/github_repo_spec.rb
+++ b/spec/models/github_repo_spec.rb
@@ -15,7 +15,6 @@ RSpec.describe GithubRepo, type: :model do
     describe "builtin validations" do
       subject { repo }
 
-      it { is_expected.to validate_presence_of(:github_id_code) }
       it { is_expected.to validate_presence_of(:name) }
       it { is_expected.to validate_presence_of(:url) }
       it { is_expected.to validate_uniqueness_of(:github_id_code) }
diff --git a/spec/models/html_variant_success_spec.rb b/spec/models/html_variant_success_spec.rb
index 392425cd0..0d84f1762 100644
--- a/spec/models/html_variant_success_spec.rb
+++ b/spec/models/html_variant_success_spec.rb
@@ -1,7 +1,6 @@
 require "rails_helper"
 
 RSpec.describe HtmlVariantSuccess, type: :model do
-  it { is_expected.to validate_presence_of(:html_variant_id) }
   it { is_expected.to belong_to(:html_variant) }
   it { is_expected.to belong_to(:article).optional }
 end
diff --git a/spec/models/html_variant_trial_spec.rb b/spec/models/html_variant_trial_spec.rb
index bebf129ec..9f3c824ca 100644
--- a/spec/models/html_variant_trial_spec.rb
+++ b/spec/models/html_variant_trial_spec.rb
@@ -1,7 +1,6 @@
 require "rails_helper"
 
 RSpec.describe HtmlVariantTrial, type: :model do
-  it { is_expected.to validate_presence_of(:html_variant_id) }
   it { is_expected.to belong_to(:html_variant) }
   it { is_expected.to belong_to(:article).optional }
 end
diff --git a/spec/models/identity_spec.rb b/spec/models/identity_spec.rb
index a6edec806..8eb46ba29 100644
--- a/spec/models/identity_spec.rb
+++ b/spec/models/identity_spec.rb
@@ -15,7 +15,6 @@ RSpec.describe Identity, type: :model do
 
       it { is_expected.to validate_presence_of(:provider) }
       it { is_expected.to validate_presence_of(:uid) }
-      it { is_expected.to validate_presence_of(:user_id) }
       it { is_expected.to validate_uniqueness_of(:uid).scoped_to(:provider) }
       it { is_expected.to validate_uniqueness_of(:user_id).scoped_to(:provider) }
 
diff --git a/spec/models/notification_subscription_spec.rb b/spec/models/notification_subscription_spec.rb
index 028aa481b..63afbadca 100644
--- a/spec/models/notification_subscription_spec.rb
+++ b/spec/models/notification_subscription_spec.rb
@@ -19,7 +19,6 @@ RSpec.describe NotificationSubscription, type: :model do
       end
 
       it { is_expected.to validate_presence_of(:config) }
-      it { is_expected.to validate_presence_of(:notifiable_id) }
       it { is_expected.to validate_presence_of(:notifiable_type) }
 
       it { is_expected.to validate_uniqueness_of(:user_id).scoped_to(%i[notifiable_type notifiable_id]) }
diff --git a/spec/models/organization_membership_spec.rb b/spec/models/organization_membership_spec.rb
index 0e2ecb68a..7c7bae1f9 100644
--- a/spec/models/organization_membership_spec.rb
+++ b/spec/models/organization_membership_spec.rb
@@ -6,8 +6,6 @@ RSpec.describe OrganizationMembership, type: :model do
 
     let(:organization) { create(:organization) }
 
-    it { is_expected.to validate_presence_of(:user_id) }
-    it { is_expected.to validate_presence_of(:organization_id) }
     it { is_expected.to validate_presence_of(:type_of_user) }
     it { is_expected.to validate_uniqueness_of(:user_id).scoped_to(:organization_id) }
     it { is_expected.to validate_inclusion_of(:type_of_user).in_array(OrganizationMembership::USER_TYPES) }
diff --git a/spec/models/podcast_episode_appearance_spec.rb b/spec/models/podcast_episode_appearance_spec.rb
index d69d70072..a1d50b4f7 100644
--- a/spec/models/podcast_episode_appearance_spec.rb
+++ b/spec/models/podcast_episode_appearance_spec.rb
@@ -9,8 +9,6 @@ RSpec.describe PodcastEpisodeAppearance, type: :model do
     it { is_expected.to belong_to(:user).inverse_of(:podcast_episode_appearances) }
     it { is_expected.to belong_to(:podcast_episode) }
 
-    it { is_expected.to validate_presence_of(:podcast_episode_id) }
-    it { is_expected.to validate_presence_of(:user_id) }
     it { is_expected.to validate_presence_of(:role) }
 
     it do
diff --git a/spec/models/podcast_ownership_spec.rb b/spec/models/podcast_ownership_spec.rb
index acd268a72..d01f560b9 100644
--- a/spec/models/podcast_ownership_spec.rb
+++ b/spec/models/podcast_ownership_spec.rb
@@ -9,8 +9,6 @@ RSpec.describe PodcastOwnership, type: :model do
     it { is_expected.to belong_to(:owner).class_name("User").with_foreign_key(:user_id).inverse_of(:podcasts_owned) }
     it { is_expected.to belong_to(:podcast) }
 
-    it { is_expected.to validate_presence_of(:podcast_id) }
-    it { is_expected.to validate_presence_of(:user_id) }
     it { is_expected.to validate_uniqueness_of(:podcast_id).scoped_to(:user_id) }
   end
 end
diff --git a/spec/models/rating_vote_spec.rb b/spec/models/rating_vote_spec.rb
index 7eeb75164..a5d520fa5 100644
--- a/spec/models/rating_vote_spec.rb
+++ b/spec/models/rating_vote_spec.rb
@@ -16,7 +16,6 @@ RSpec.describe RatingVote, type: :model do
       it { is_expected.to validate_inclusion_of(:context).in_array(%w[explicit readinglist_reaction comment]) }
       it { is_expected.to validate_inclusion_of(:group).in_array(%w[experience_level]) }
       it { is_expected.to validate_numericality_of(:rating).is_greater_than(0.0).is_less_than_or_equal_to(10.0) }
-      it { is_expected.to validate_presence_of(:user_id).on(:create) }
       it { is_expected.to validate_uniqueness_of(:user_id).scoped_to(%i[article_id context]) }
     end
   end
diff --git a/spec/models/sponsorship_spec.rb b/spec/models/sponsorship_spec.rb
index 71eae0a39..edaa540fd 100644
--- a/spec/models/sponsorship_spec.rb
+++ b/spec/models/sponsorship_spec.rb
@@ -52,9 +52,7 @@ RSpec.describe Sponsorship, type: :model do
       it { is_expected.to validate_inclusion_of(:status).in_array(Sponsorship::STATUSES) }
 
       it { is_expected.to validate_presence_of(:level) }
-      it { is_expected.to validate_presence_of(:organization) }
       it { is_expected.to validate_presence_of(:status) }
-      it { is_expected.to validate_presence_of(:user) }
 
       it { is_expected.not_to allow_values(nil).for(:featured_number) }
       it { is_expected.to allow_values(nil).for(:expires_at) }
diff --git a/spec/models/tag_adjustment_spec.rb b/spec/models/tag_adjustment_spec.rb
index 85d18d7b0..b1796f8a3 100644
--- a/spec/models/tag_adjustment_spec.rb
+++ b/spec/models/tag_adjustment_spec.rb
@@ -12,9 +12,6 @@ RSpec.describe TagAdjustment, type: :model do
   let(:mod_user) { create(:user) }
   let(:regular_user) { create(:user) }
 
-  it { is_expected.to validate_presence_of(:user_id) }
-  it { is_expected.to validate_presence_of(:article_id) }
-  it { is_expected.to validate_presence_of(:tag_id) }
   it { is_expected.to validate_presence_of(:tag_name) }
   it { is_expected.to validate_presence_of(:adjustment_type) }
   it { is_expected.to validate_presence_of(:status) }
diff --git a/spec/models/tweet_spec.rb b/spec/models/tweet_spec.rb
index 26cb0691b..b1cb53587 100644
--- a/spec/models/tweet_spec.rb
+++ b/spec/models/tweet_spec.rb
@@ -5,7 +5,6 @@ RSpec.describe Tweet, type: :model, vcr: true do
   let(:tweet_reply_id) { "1242938461784608770" }
   let(:retweet_id) { "1262395854469677058" }
 
-  it { is_expected.to validate_presence_of(:twitter_id_code) }
   it { is_expected.to validate_presence_of(:full_fetched_object_serialized) }
 
   describe ".find_or_fetch" do
diff --git a/spec/models/user_subscription_spec.rb b/spec/models/user_subscription_spec.rb
index ae0ea24c4..54086336e 100644
--- a/spec/models/user_subscription_spec.rb
+++ b/spec/models/user_subscription_spec.rb
@@ -7,11 +7,8 @@ RSpec.describe UserSubscription, type: :model do
   let(:source) { create(:article, :with_user_subscription_tag_role_user, with_user_subscription_tag: true) }
 
   describe "validations" do
-    it { is_expected.to validate_presence_of(:user_subscription_sourceable_id) }
     it { is_expected.to validate_presence_of(:user_subscription_sourceable_type) }
-    it { is_expected.to validate_presence_of(:subscriber_id) }
     it { is_expected.to validate_presence_of(:subscriber_email) }
-    it { is_expected.to validate_presence_of(:author_id) }
     it { is_expected.to validate_inclusion_of(:user_subscription_sourceable_type).in_array(%w[Article]) }
 
     # rubocop:disable RSpec/NamedSubject