diff --git a/.github/workflows/update-pr-spreadsheet.yml b/.github/workflows/update-pr-spreadsheet.yml
new file mode 100644
index 0000000000..e7b3d125ee
--- /dev/null
+++ b/.github/workflows/update-pr-spreadsheet.yml
@@ -0,0 +1,16 @@
+name: Update community pull requests spreadsheet
+on:
+  pull_request_target:
+    types: [opened, reopened, edited, closed, synchronize, assigned, unassigned, review_requested, review_request_removed]
+  pull_request_review:
+    types: [submitted, edited, dismissed]
+  issue_comment:
+    types: [created, edited, deleted]
+
+jobs:
+  call-update-spreadsheet:
+    uses: learningequality/.github/.github/workflows/update-pr-spreadsheet.yml@main
+    secrets:
+      CONTRIBUTIONS_SPREADSHEET_ID: ${{ secrets.CONTRIBUTIONS_SPREADSHEET_ID }}
+      CONTRIBUTIONS_SHEET_NAME: ${{ secrets.CONTRIBUTIONS_SHEET_NAME }}
+      GH_UPLOADER_GCP_SA_CREDENTIALS: ${{ secrets.GH_UPLOADER_GCP_SA_CREDENTIALS }}
diff --git a/contentcuration/contentcuration/apps.py b/contentcuration/contentcuration/apps.py
index 6d0fa858ff..2466492feb 100644
--- a/contentcuration/contentcuration/apps.py
+++ b/contentcuration/contentcuration/apps.py
@@ -8,6 +8,9 @@ class ContentConfig(AppConfig):
     name = 'contentcuration'
 
     def ready(self):
+        # Import signals
+        import contentcuration.signals  # noqa
+
         if settings.AWS_AUTO_CREATE_BUCKET and not is_gcs_backend():
             from contentcuration.utils.minio_utils import ensure_storage_bucket_public
             ensure_storage_bucket_public()
diff --git a/contentcuration/contentcuration/frontend/channelEdit/components/move/MoveModal.vue b/contentcuration/contentcuration/frontend/channelEdit/components/move/MoveModal.vue
index a68c50d51b..5865f28d30 100644
--- a/contentcuration/contentcuration/frontend/channelEdit/components/move/MoveModal.vue
+++ b/contentcuration/contentcuration/frontend/channelEdit/components/move/MoveModal.vue
@@ -98,6 +98,11 @@
             <VDivider v-if="index < children.length - 1" :key="`move-divider-${node.id}`" />
           </template>
         </VList>
+        <div class="show-more-button-container">
+          <KButton v-if="more" :disabled="moreLoading" @click="loadMore">
+            {{ showMoreLabel }}
+          </KButton>
+        </div>
       </VFlex>
       <ResourceDrawer
         :nodeId="previewNodeId"
@@ -146,6 +151,13 @@
   import Thumbnail from 'shared/views/files/Thumbnail';
   import { ContentKindsNames } from 'shared/leUtils/ContentKinds';
   import { titleMixin } from 'shared/mixins';
+  import { createTranslator } from 'shared/i18n';
+
+  // Can't use cross component translator to get the NodePanel translations
+  // here, because the NodePanel component imports this component.
+  const showMoreTranslator = createTranslator('NodePanel', {
+    showMore: 'Show more',
+  });
 
   export default {
     name: 'MoveModal',
@@ -182,6 +194,8 @@
       return {
         showNewTopicModal: false,
         loading: false,
+        more: null,
+        moreLoading: false,
         moveNodesInProgress: false,
         targetNodeId: null,
         previewNodeId: null,
@@ -234,6 +248,10 @@
       crumbs() {
         return this.getContentNodeAncestors(this.targetNodeId, true) || [];
       },
+      showMoreLabel() {
+        // eslint-disable-next-line kolibri/vue-no-undefined-string-uses
+        return showMoreTranslator.$tr('showMore');
+      },
     },
     watch: {
       targetNodeId() {
@@ -247,7 +265,7 @@
       this.targetNodeId = this.currentLocationId || this.rootId;
     },
     methods: {
-      ...mapActions('contentNode', ['createContentNode', 'loadChildren']),
+      ...mapActions('contentNode', ['createContentNode', 'loadChildren', 'loadContentNodes']),
       isDisabled(node) {
         return this.moveNodeIds.includes(node.id);
       },
@@ -272,8 +290,9 @@
           return this.loadChildren({
             parent: this.targetNodeId,
             root_id: this.rootId,
-          }).then(() => {
+          }).then(childrenResponse => {
             this.loading = false;
+            this.more = childrenResponse.more || null;
           });
         }
         return Promise.resolve();
@@ -302,6 +321,15 @@
         });
         this.moveNodesInProgress = false;
       },
+      loadMore() {
+        if (this.more && !this.moreLoading) {
+          this.moreLoading = true;
+          this.loadContentNodes(this.more).then(response => {
+            this.more = response.more || null;
+            this.moreLoading = false;
+          });
+        }
+      },
     },
     $trs: {
       moveItems:
@@ -350,4 +378,11 @@
     }
   }
 
+  .show-more-button-container {
+    display: flex;
+    justify-content: center;
+    width: 100%;
+    margin-bottom: 10px;
+  }
+
 </style>
diff --git a/contentcuration/contentcuration/frontend/channelEdit/views/CurrentTopicView.vue b/contentcuration/contentcuration/frontend/channelEdit/views/CurrentTopicView.vue
index a994e1c9aa..943e7c2836 100644
--- a/contentcuration/contentcuration/frontend/channelEdit/views/CurrentTopicView.vue
+++ b/contentcuration/contentcuration/frontend/channelEdit/views/CurrentTopicView.vue
@@ -533,6 +533,7 @@
       },
       inheritanceParent() {
         const firstNode = this.currentInheritingNodes[0];
+
         if (!firstNode) {
           return;
         }
@@ -726,6 +727,7 @@
       handleDragDrop(drop) {
         const { data } = drop;
         const { identity, section, relative } = data.target;
+        const targetMetadata = identity.metadata || {};
         const isTargetTree =
           drop.target && drop.target.region && drop.target.region.id === DraggableRegions.TREE;
 
@@ -742,7 +744,7 @@
           position = this.relativePosition(relative > DraggableFlags.NONE ? relative : section);
         } else {
           // Safety check
-          const { kind } = identity.metadata || {};
+          const { kind } = targetMetadata;
           if (kind && kind !== ContentKindsNames.TOPIC) {
             return Promise.reject('Cannot set child of non-topic');
           }
@@ -756,7 +758,7 @@
         const sources = drop.sources || [];
         const sourceRegion = sources.length > 0 ? sources[0].region : null;
         const payload = {
-          target: identity.metadata.id,
+          target: targetMetadata.id,
           position,
         };
 
@@ -765,7 +767,7 @@
           // `excluded_descendants` by accessing the copy trees through the clipboard node ID
           if (sourceRegion && sourceRegion.id === DraggableRegions.CLIPBOARD) {
             return Promise.all(
-              data.sources.map(source => {
+              sources.map(source => {
                 // Using `getCopyTrees` we can access the `excluded_descendants` for the node, such
                 // that we make sure to skip copying nodes that aren't intended to be copied
                 const trees = this.getCopyTrees(source.metadata.clipboardNodeId, true);
@@ -789,10 +791,27 @@
             );
           }
 
+          // We want to avoid launching the inherit modal when the move operation is a prepend or
+          // append move, and target is the current parent. When the move operation is relative to
+          // the target, that is left or right, we want only launch the modal if the parent is
+          // changing
+          let inherit = false;
+          if (
+            position === RELATIVE_TREE_POSITIONS.FIRST_CHILD ||
+            position === RELATIVE_TREE_POSITIONS.LAST_CHILD
+          ) {
+            inherit = !sources.some(s => s.metadata.parent === targetMetadata.id);
+          } else if (
+            position === RELATIVE_TREE_POSITIONS.LEFT ||
+            position === RELATIVE_TREE_POSITIONS.RIGHT
+          ) {
+            inherit = !sources.some(s => s.metadata.parent === targetMetadata.parent);
+          }
+
           return this.moveContentNodes({
             ...payload,
-            id__in: data.sources.map(s => s.metadata.id),
-            inherit: !data.sources.some(s => s.metadata.parent === payload.target),
+            id__in: sources.map(s => s.metadata.id),
+            inherit,
           });
         }
       },
diff --git a/contentcuration/contentcuration/frontend/channelEdit/views/ImportFromChannels/ContentTreeList.vue b/contentcuration/contentcuration/frontend/channelEdit/views/ImportFromChannels/ContentTreeList.vue
index 72d046d3dd..8b2bf39ac6 100644
--- a/contentcuration/contentcuration/frontend/channelEdit/views/ImportFromChannels/ContentTreeList.vue
+++ b/contentcuration/contentcuration/frontend/channelEdit/views/ImportFromChannels/ContentTreeList.vue
@@ -43,6 +43,11 @@
           />
         </VFlex>
       </VLayout>
+      <div class="show-more-button-container">
+        <KButton v-if="more" :disabled="moreLoading" @click="loadMore">
+          {{ showMoreLabel }}
+        </KButton>
+      </div>
     </div>
   </VContainer>
 
@@ -55,6 +60,7 @@
   import intersectionBy from 'lodash/intersectionBy';
   import { mapActions, mapGetters } from 'vuex';
   import find from 'lodash/find';
+  import NodePanel from '../NodePanel';
   import { RouteNames } from '../../constants';
   import BrowsingCard from './BrowsingCard';
   import Breadcrumbs from 'shared/views/Breadcrumbs';
@@ -62,6 +68,9 @@
   import LoadingText from 'shared/views/LoadingText';
   import { constantsTranslationMixin } from 'shared/mixins';
   import { ChannelListTypes } from 'shared/constants';
+  import { crossComponentTranslator } from 'shared/i18n';
+
+  const showMoreTranslator = crossComponentTranslator(NodePanel);
 
   export default {
     name: 'ContentTreeList',
@@ -85,6 +94,8 @@
     data() {
       return {
         loading: false,
+        more: null,
+        moreLoading: false,
       };
     },
     computed: {
@@ -142,39 +153,44 @@
           ...ancestorsLinks,
         ];
       },
+      showMoreLabel() {
+        // eslint-disable-next-line kolibri/vue-no-undefined-string-uses
+        return showMoreTranslator.$tr('showMore');
+      },
     },
     watch: {
-      topicId(parent) {
+      topicId(newTopicId, oldTopicId) {
+        if (newTopicId !== oldTopicId && newTopicId) {
+          this.loadData();
+        }
+      },
+    },
+    created() {
+      this.loadData();
+    },
+    methods: {
+      ...mapActions('contentNode', ['loadChildren', 'loadAncestors', 'loadContentNodes']),
+      loadData() {
         this.loading = true;
-        return this.loadChildren({
-          parent,
+        const params = {
           complete: true,
-        }).then(() => {
+        };
+        const channelListType = this.$route.query.channel_list || ChannelListTypes.PUBLIC;
+        if (channelListType === ChannelListTypes.PUBLIC) {
+          // TODO: load from public API instead
+          // TODO: challenging because of node_id->id and root_id->channel_id
+          params.published = true;
+        }
+
+        return Promise.all([
+          this.loadChildren({ parent: this.topicId, ...params }).then(childrenResponse => {
+            this.more = childrenResponse.more || null;
+          }),
+          this.loadAncestors({ id: this.topicId }),
+        ]).then(() => {
           this.loading = false;
         });
       },
-    },
-    mounted() {
-      this.loading = true;
-      const params = {
-        complete: true,
-      };
-      const channelListType = this.$route.query.channel_list || ChannelListTypes.PUBLIC;
-      if (channelListType === ChannelListTypes.PUBLIC) {
-        // TODO: load from public API instead
-        // TODO: challenging because of node_id->id and root_id->channel_id
-        params.published = true;
-      }
-
-      return Promise.all([
-        this.loadChildren({ parent: this.topicId, ...params }),
-        this.loadAncestors({ id: this.topicId }),
-      ]).then(() => {
-        this.loading = false;
-      });
-    },
-    methods: {
-      ...mapActions('contentNode', ['loadChildren', 'loadAncestors']),
       // @public
       scrollToNode(nodeId) {
         const ref = this.$refs[nodeId];
@@ -187,6 +203,15 @@
       toggleSelected(node) {
         this.$emit('change_selected', { nodes: [node], isSelected: !this.isSelected(node) });
       },
+      loadMore() {
+        if (this.more && !this.moreLoading) {
+          this.moreLoading = true;
+          this.loadContentNodes(this.more).then(response => {
+            this.more = response.more || null;
+            this.moreLoading = false;
+          });
+        }
+      },
     },
     $trs: {
       allChannelsLabel: 'Channels',
diff --git a/contentcuration/contentcuration/frontend/channelEdit/views/TreeView/TreeViewBase.vue b/contentcuration/contentcuration/frontend/channelEdit/views/TreeView/TreeViewBase.vue
index 2de7cae031..0f8ba07b3c 100644
--- a/contentcuration/contentcuration/frontend/channelEdit/views/TreeView/TreeViewBase.vue
+++ b/contentcuration/contentcuration/frontend/channelEdit/views/TreeView/TreeViewBase.vue
@@ -390,7 +390,7 @@
           this.currentChannel.publishing ||
           !this.isChanged ||
           !this.currentChannel.language ||
-          (this.rootNode && !this.rootNode.total_count)
+          (this.rootNode && !this.rootNode.resource_count)
         );
       },
       publishButtonTooltip() {
diff --git a/contentcuration/contentcuration/frontend/channelEdit/views/trash/TrashModal.vue b/contentcuration/contentcuration/frontend/channelEdit/views/trash/TrashModal.vue
index edbd7eea3e..e1ba3e3625 100644
--- a/contentcuration/contentcuration/frontend/channelEdit/views/trash/TrashModal.vue
+++ b/contentcuration/contentcuration/frontend/channelEdit/views/trash/TrashModal.vue
@@ -66,6 +66,11 @@
               </tr>
             </template>
           </VDataTable>
+          <div class="show-more-button-container">
+            <KButton v-if="more" :disabled="moreLoading" @click="loadMore">
+              {{ showMoreLabel }}
+            </KButton>
+          </div>
         </VCard>
       </VContainer>
       <ResourceDrawer
@@ -127,6 +132,7 @@
 
   import { mapActions, mapGetters } from 'vuex';
   import sortBy from 'lodash/sortBy';
+  import NodePanel from '../NodePanel';
   import MoveModal from '../../components/move/MoveModal';
   import ResourceDrawer from '../../components/ResourceDrawer';
   import { RouteNames } from '../../constants';
@@ -136,6 +142,9 @@
   import LoadingText from 'shared/views/LoadingText';
   import FullscreenModal from 'shared/views/FullscreenModal';
   import { titleMixin, routerMixin } from 'shared/mixins';
+  import { crossComponentTranslator } from 'shared/i18n';
+
+  const showMoreTranslator = crossComponentTranslator(NodePanel);
 
   export default {
     name: 'TrashModal',
@@ -159,6 +168,8 @@
       return {
         dialog: true,
         loading: false,
+        more: null,
+        moreLoading: false,
         previewNodeId: null,
         selected: [],
         showConfirmationDialog: false,
@@ -190,7 +201,7 @@
         ];
       },
       items() {
-        return sortBy(this.getContentNodeChildren(this.trashId), 'modified').reverse();
+        return sortBy(this.getContentNodeChildren(this.trashId), 'modified');
       },
       backLink() {
         return {
@@ -201,6 +212,10 @@
       counts() {
         return this.getTopicAndResourceCounts(this.selected);
       },
+      showMoreLabel() {
+        // eslint-disable-next-line kolibri/vue-no-undefined-string-uses
+        return showMoreTranslator.$tr('showMore');
+      },
     },
     watch: {
       dialog(newValue) {
@@ -210,21 +225,12 @@
       },
     },
     created() {
-      Promise.all([
-        this.loadContentNodes({ parent__in: [this.rootId] }),
+      this.loadContentNodes({ parent__in: [this.rootId] }),
         this.loadAncestors({ id: this.nodeId }),
-      ]);
+        this.loadNodes();
     },
     mounted() {
-      this.loading = true;
-      if (!this.trashId) {
-        this.loading = false;
-        return;
-      }
       this.updateTabTitle(this.$store.getters.appendChannelName(this.$tr('trashModalTitle')));
-      this.loadChildren({ parent: this.trashId }).then(() => {
-        this.loading = false;
-      });
     },
     methods: {
       ...mapActions('contentNode', [
@@ -234,6 +240,17 @@
         'loadContentNodes',
         'loadAncestors',
       ]),
+      loadNodes() {
+        this.loading = true;
+        if (!this.trashId) {
+          this.loading = false;
+          return;
+        }
+        this.loadChildren({ parent: this.trashId }).then(childrenResponse => {
+          this.loading = false;
+          this.more = childrenResponse.more || null;
+        });
+      },
       moveNodes(target) {
         return this.moveContentNodes({
           id__in: this.selected,
@@ -242,6 +259,8 @@
         }).then(() => {
           this.reset();
           this.$refs.moveModal && this.$refs.moveModal.moveComplete();
+          // Reload after this to ensure that anything over the pagination fold is loaded now
+          this.loadNodes();
         });
       },
       reset() {
@@ -254,6 +273,8 @@
           this.showConfirmationDialog = false;
           this.reset();
           this.$store.dispatch('showSnackbar', { text });
+          // Reload after this to ensure that anything over the pagination fold is loaded now
+          this.loadNodes();
         });
       },
       toggleSelectAll(selectAll) {
@@ -262,6 +283,15 @@
       getItemBackground(id) {
         return this.previewNodeId === id ? this.$vuetify.theme.greyBackground : 'transparent';
       },
+      loadMore() {
+        if (this.more && !this.moreLoading) {
+          this.moreLoading = true;
+          this.loadContentNodes(this.more).then(response => {
+            this.more = response.more || null;
+            this.moreLoading = false;
+          });
+        }
+      },
     },
     $trs: {
       trashModalTitle: 'Trash',
@@ -283,4 +313,10 @@
 </script>
 <style lang="less" scoped>
 
+  .show-more-button-container {
+    display: flex;
+    justify-content: center;
+    width: 100%;
+  }
+
 </style>
diff --git a/contentcuration/contentcuration/frontend/channelEdit/views/trash/__tests__/trashModal.spec.js b/contentcuration/contentcuration/frontend/channelEdit/views/trash/__tests__/trashModal.spec.js
index fd75caa234..4d4db70575 100644
--- a/contentcuration/contentcuration/frontend/channelEdit/views/trash/__tests__/trashModal.spec.js
+++ b/contentcuration/contentcuration/frontend/channelEdit/views/trash/__tests__/trashModal.spec.js
@@ -55,7 +55,7 @@ function makeWrapper(items) {
     methods: {
       loadContentNodes: jest.fn(),
       loadAncestors: jest.fn(),
-      loadChildren: jest.fn(() => Promise.resolve()),
+      loadChildren: jest.fn(() => Promise.resolve({ more: null, results: [] })),
     },
     stubs: {
       ResourceDrawer: true,
diff --git a/contentcuration/contentcuration/frontend/shared/data/resources.js b/contentcuration/contentcuration/frontend/shared/data/resources.js
index eebbcdf0ad..3c0c74fbea 100644
--- a/contentcuration/contentcuration/frontend/shared/data/resources.js
+++ b/contentcuration/contentcuration/frontend/shared/data/resources.js
@@ -1998,7 +1998,7 @@ export const User = new Resource({
   uuid: false,
 
   updateAsAdmin(id, changes) {
-    return client.post(window.Urls.adminUsersAccept(id)).then(() => {
+    return client.patch(window.Urls.adminUsersDetail(id), changes).then(() => {
       return this.transaction({ mode: 'rw' }, () => {
         return this.table.update(id, changes);
       });
diff --git a/contentcuration/contentcuration/frontend/shared/mixins.js b/contentcuration/contentcuration/frontend/shared/mixins.js
index 01095f6df2..58cc27b727 100644
--- a/contentcuration/contentcuration/frontend/shared/mixins.js
+++ b/contentcuration/contentcuration/frontend/shared/mixins.js
@@ -141,6 +141,7 @@ export const constantStrings = createTranslator('ConstantStrings', {
   low_res_video: 'Low resolution',
   video_subtitle: 'Captions',
   html5_zip: 'HTML5 zip',
+  imscp_zip: 'IMSCP zip',
   video_thumbnail: 'Thumbnail',
   audio_thumbnail: 'Thumbnail',
   document_thumbnail: 'Thumbnail',
diff --git a/contentcuration/contentcuration/frontend/shared/views/channel/ChannelDetailsModal.vue b/contentcuration/contentcuration/frontend/shared/views/channel/ChannelDetailsModal.vue
index e336bb5340..017fe11f12 100644
--- a/contentcuration/contentcuration/frontend/shared/views/channel/ChannelDetailsModal.vue
+++ b/contentcuration/contentcuration/frontend/shared/views/channel/ChannelDetailsModal.vue
@@ -21,10 +21,10 @@
             </VBtn>
           </template>
           <VList>
-            <VListTile @click="generatePdf">
+            <VListTile @click="generatePDF">
               <VListTileTitle>{{ $tr('downloadPDF') }}</VListTileTitle>
             </VListTile>
-            <VListTile data-test="dl-csv" @click="generateChannelsCSV([channelWithDetails])">
+            <VListTile data-test="dl-csv" @click="generateCSV">
               <VListTileTitle>{{ $tr('downloadCSV') }}</VListTileTitle>
             </VListTile>
           </VList>
@@ -114,14 +114,26 @@
     },
     mounted() {
       this.load();
+      this.$analytics.trackAction('channel_details', 'View', {
+        id: this.channelId,
+      });
     },
     methods: {
       ...mapActions('channel', ['loadChannel', 'loadChannelDetails']),
-      async generatePdf() {
+      async generatePDF() {
+        this.$analytics.trackEvent('channel_details', 'Download PDF', {
+          id: this.channelId,
+        });
         this.loading = true;
         await this.generateChannelsPDF([this.channelWithDetails]);
         this.loading = false;
       },
+      generateCSV() {
+        this.$analytics.trackEvent('channel_details', 'Download CSV', {
+          id: this.channelId,
+        });
+        this.generateChannelsCSV([this.channelWithDetails]);
+      },
       load() {
         this.loading = true;
         const channelPromise = this.loadChannel(this.channelId);
diff --git a/contentcuration/contentcuration/frontend/shared/views/details/Details.vue b/contentcuration/contentcuration/frontend/shared/views/details/Details.vue
index a94b960214..03ace0c8fd 100644
--- a/contentcuration/contentcuration/frontend/shared/views/details/Details.vue
+++ b/contentcuration/contentcuration/frontend/shared/views/details/Details.vue
@@ -262,7 +262,7 @@
             <VFlex class="source-thumbnail">
               <Thumbnail :src="channel.thumbnail" />
             </VFlex>
-            <VFlex v-if="libraryMode" class="font-weight-bold notranslate px-4 subheading">
+            <VFlex v-if="printing" class="font-weight-bold notranslate px-4 subheading">
               {{ channel.name }}
             </VFlex>
             <a
@@ -419,9 +419,6 @@
         }
         return '';
       },
-      libraryMode() {
-        return window.libraryMode;
-      },
       sizeText() {
         const size = this._details.resource_size;
         const sizeIndex = Math.max(
@@ -496,6 +493,14 @@
         return this.categories.join(', ');
       },
     },
+    mounted() {
+      if (!this.isChannel) {
+        // Track node details view when not a channel-- is this happening?
+        this.$analytics.trackAction('node_details', 'View', {
+          id: this._details.id,
+        });
+      }
+    },
     methods: {
       channelUrl(channel) {
         return window.Urls.channel(channel.id);
diff --git a/contentcuration/contentcuration/models.py b/contentcuration/contentcuration/models.py
index 690325fc3c..7d1d1ca7ab 100644
--- a/contentcuration/contentcuration/models.py
+++ b/contentcuration/contentcuration/models.py
@@ -22,6 +22,7 @@
 from django.core.mail import send_mail
 from django.core.validators import MaxValueValidator
 from django.core.validators import MinValueValidator
+from django.db import connection
 from django.db import IntegrityError
 from django.db import models
 from django.db.models import Count
@@ -45,6 +46,7 @@
 from django.dispatch import receiver
 from django.utils import timezone
 from django.utils.translation import gettext as _
+from django_cte import CTEManager
 from django_cte import With
 from le_utils import proquint
 from le_utils.constants import content_kinds
@@ -261,9 +263,13 @@ def hard_delete_user_related_data(self):
             editable_channels_user_query, field="id")).filter(num_editors=1, public=False)
 
         # Point sole editor non-public channels' contentnodes to orphan tree to let
-        # our garbage collection delete the nodes and underlying files.
-        ContentNode._annotate_channel_id(ContentNode.objects).filter(channel_id__in=list(
-            non_public_channels_sole_editor.values_list("id", flat=True))).update(parent_id=settings.ORPHANAGE_ROOT_ID)
+        # our garbage collection delete the nodes and underlying file.
+        tree_ids_to_update = non_public_channels_sole_editor.values_list('main_tree__tree_id', flat=True)
+
+        for tree_id in tree_ids_to_update:
+            ContentNode.objects.filter(tree_id=tree_id).update(parent_id=settings.ORPHANAGE_ROOT_ID)
+
+        logging.debug("Queries after updating content nodes parent ID: %s", connection.queries)
 
         # Hard delete non-public channels associated with this user (if user is the only editor).
         non_public_channels_sole_editor.delete()
@@ -1055,6 +1061,18 @@ def mark_publishing(self, user):
         self.main_tree.publishing = True
         self.main_tree.save()
 
+    def get_server_rev(self):
+        changes_cte = With(
+            Change.objects.filter(channel=self).values("server_rev", "applied"),
+        )
+        return (
+            changes_cte.queryset()
+            .with_cte(changes_cte)
+            .filter(applied=True)
+            .values_list("server_rev", flat=True)
+            .order_by("-server_rev").first()
+        ) or 0
+
     @property
     def deletion_history(self):
         return self.history.filter(action=channel_history.DELETION)
@@ -1551,7 +1569,7 @@ def get_nodes_with_title(cls, title, limit_to_children_of=None):
             return root.get_descendants().filter(title=title)
         return cls.objects.filter(title=title)
 
-    def get_details(self, channel_id=None):
+    def get_details(self, channel=None):
         """
         Returns information about the node and its children, including total size, languages, files, etc.
 
@@ -1570,12 +1588,13 @@ def get_details(self, channel_id=None):
             .values("id")
         )
 
-        if channel_id:
-            channel = Channel.objects.filter(id=channel_id)[0]
-        else:
+        # Get resources
+        resources = descendants.exclude(kind=content_kinds.TOPIC).order_by()
+
+        if not channel:
             channel = self.get_channel()
 
-        if not descendants.exists():
+        if not resources.exists():
             data = {
                 "last_update": pytz.utc.localize(datetime.now()).strftime(
                     settings.DATE_TIME_FORMAT
@@ -1604,8 +1623,6 @@ def get_details(self, channel_id=None):
             cache.set("details_{}".format(self.node_id), json.dumps(data), None)
             return data
 
-        # Get resources
-        resources = descendants.exclude(kind=content_kinds.TOPIC).order_by()
         nodes = With(
             File.objects.filter(contentnode_id__in=Subquery(resources.values("id")))
             .values("checksum", "file_size")
@@ -1816,10 +1833,10 @@ def get_details(self, channel_id=None):
             "sample_pathway": pathway,
             "sample_nodes": sample_nodes,
             # source model fields for the below default to an empty string, but can also be null
-            "authors": list(filter(bool, node["authors"])),
-            "aggregators": list(filter(bool, node["aggregators"])),
-            "providers": list(filter(bool, node["providers"])),
-            "copyright_holders": list(filter(bool, node["copyright_holders"])),
+            "authors": list(filter(bool, node["authors"] or [])),
+            "aggregators": list(filter(bool, node["aggregators"] or [])),
+            "providers": list(filter(bool, node["providers"] or [])),
+            "copyright_holders": list(filter(bool, node["copyright_holders"] or [])),
             "levels": node.get("levels") or [],
             "categories": node.get("all_categories") or [],
         }
@@ -2567,6 +2584,8 @@ class Change(models.Model):
     # will be falsy.
     unpublishable = models.BooleanField(null=True, blank=True, default=False)
 
+    objects = CTEManager()
+
     @classmethod
     def _create_from_change(
         cls,
diff --git a/contentcuration/contentcuration/signals.py b/contentcuration/contentcuration/signals.py
new file mode 100644
index 0000000000..e96446569f
--- /dev/null
+++ b/contentcuration/contentcuration/signals.py
@@ -0,0 +1,18 @@
+from django.db.backends.postgresql.features import DatabaseFeatures
+from django.db.backends.signals import connection_created
+from django.dispatch import receiver
+
+
+@receiver(connection_created)
+def set_jit(sender, connection, **kwargs):
+    """
+    Disable Just-In-Time compilation for PostgreSQL databases >= 11, at least until we can
+    optimize its use.
+    https://www.postgresql.org/docs/12/runtime-config-query.html#GUC-JIT
+    """
+    if connection.vendor == 'postgresql':
+        db_features = DatabaseFeatures(connection)
+        # JIT is new in v11, and for reference this returns True for v11 and following
+        if db_features.is_postgresql_11:
+            with connection.cursor() as cursor:
+                cursor.execute("SET jit = 'off';")
diff --git a/contentcuration/contentcuration/tests/test_models.py b/contentcuration/contentcuration/tests/test_models.py
index 0f910fb7ec..9c093369cd 100644
--- a/contentcuration/contentcuration/tests/test_models.py
+++ b/contentcuration/contentcuration/tests/test_models.py
@@ -15,6 +15,7 @@
 from contentcuration.constants import channel_history
 from contentcuration.constants import user_history
 from contentcuration.models import AssessmentItem
+from contentcuration.models import Change
 from contentcuration.models import Channel
 from contentcuration.models import ChannelHistory
 from contentcuration.models import ChannelSet
@@ -32,6 +33,7 @@
 from contentcuration.models import UserHistory
 from contentcuration.tests import testdata
 from contentcuration.tests.base import StudioTestCase
+from contentcuration.viewsets.sync.constants import DELETED
 
 
 @pytest.fixture
@@ -251,6 +253,29 @@ def test_filter_edit_queryset__private_channel__anonymous(self):
         queryset = Channel.filter_edit_queryset(self.base_queryset, user=self.anonymous_user)
         self.assertQuerysetDoesNotContain(queryset, pk=channel.id)
 
+    def test_get_server_rev(self):
+        channel = testdata.channel()
+
+        def create_change(server_rev, applied):
+            return Change(
+                channel=channel,
+                server_rev=server_rev,
+                user=self.admin_user,
+                created_by=self.admin_user,
+                change_type=DELETED,
+                table=Channel.__name__,
+                applied=applied,
+                kwargs={},
+            )
+
+        Change.objects.bulk_create([
+            create_change(1, True),
+            create_change(2, True),
+            create_change(3, False),
+        ])
+
+        self.assertEqual(channel.get_server_rev(), 2)
+
 
 class ContentNodeTestCase(PermissionQuerysetTestCase):
     @property
diff --git a/contentcuration/contentcuration/tests/views/test_nodes.py b/contentcuration/contentcuration/tests/views/test_nodes.py
index 2367263275..a981b84ca7 100644
--- a/contentcuration/contentcuration/tests/views/test_nodes.py
+++ b/contentcuration/contentcuration/tests/views/test_nodes.py
@@ -1,5 +1,6 @@
 import datetime
 import json
+from contextlib import contextmanager
 
 import pytz
 from django.conf import settings
@@ -8,11 +9,16 @@
 from mock import Mock
 from mock import patch
 
+from contentcuration.models import ContentNode
 from contentcuration.tasks import generatenodediff_task
 from contentcuration.tests.base import BaseAPITestCase
 
 
 class NodesViewsTestCase(BaseAPITestCase):
+    def tearDown(self):
+        super().tearDown()
+        cache.clear()
+
     def test_get_node_diff__missing_contentnode(self):
         response = self.get(reverse("get_node_diff", kwargs=dict(updated_id="abc123", original_id="def456")))
         self.assertEqual(response.status_code, 404)
@@ -32,29 +38,139 @@ def test_get_node_diff__task_processing(self, mock_find_incomplete_ids):
         response = self.get(reverse("get_node_diff", kwargs=dict(updated_id=pk, original_id=pk)))
         self.assertEqual(response.status_code, 302)
 
-    def test_get_channel_details(self):
-        url = reverse('get_channel_details', kwargs={"channel_id": self.channel.id})
-        response = self.get(url)
 
+class DetailsTestCase(BaseAPITestCase):
+    def setUp(self):
+        super().setUp()
+        self.default_details = {
+            "resource_count": 5,
+            "resource_size": 100,
+            "kind_count": {"document": 3, "video": 2}
+        }
+        # see tree.json for where this comes from
+        self.node = ContentNode.objects.get(node_id="00000000000000000000000000000001")
+        # required by get_node_details
+        self.channel.make_public()
+
+    def tearDown(self):
+        super().tearDown()
+        cache.clear()
+
+    def _set_cache(self, node, last_update=None):
+        data = self.default_details.copy()
+        if last_update is not None:
+            data.update(last_update=pytz.utc.localize(last_update).strftime(settings.DATE_TIME_FORMAT))
+
+        cache_key = "details_{}".format(node.node_id)
+        cache.set(cache_key, json.dumps(data))
+
+    @contextmanager
+    def _check_details(self, node=None):
+        endpoint = "get_channel_details" if node is None else "get_node_details"
+        param = {"channel_id": self.channel.id} \
+            if endpoint == "get_channel_details" \
+            else {"node_id": node.id}
+        url = reverse(endpoint, kwargs=param)
+        response = self.get(url)
+        print(response.content)
         details = json.loads(response.content)
-        assert details['resource_count'] > 0
-        assert details['resource_size'] > 0
-        assert len(details['kind_count']) > 0
+        yield details
+
+    def assertDetailsEqual(self, details, expected):
+        self.assertEqual(details['resource_count'], expected['resource_count'])
+        self.assertEqual(details['resource_size'], expected['resource_size'])
+        self.assertEqual(details['kind_count'], expected['kind_count'])
+
+    @patch("contentcuration.models.ContentNode.get_details")
+    def test_get_channel_details__uncached(self, mock_get_details):
+        mock_get_details.return_value = {
+            "resource_count": 7,
+            "resource_size": 200,
+            "kind_count": {"document": 33, "video": 22}
+        }
+        with self._check_details() as details:
+            self.assertDetailsEqual(details, mock_get_details.return_value)
 
-    def test_get_channel_details_cached(self):
-        cache_key = "details_{}".format(self.channel.main_tree.id)
+        mock_get_details.assert_called_once_with(channel=self.channel)
 
+    @patch("contentcuration.views.nodes.getnodedetails_task")
+    def test_get_channel_details__cached(self, task_mock):
         # force the cache to update by adding a very old cache entry. Since Celery tasks run sync in the test suite,
         # get_channel_details will return an updated cache value rather than generate it async.
-        data = {"last_update": pytz.utc.localize(datetime.datetime(1990, 1, 1)).strftime(settings.DATE_TIME_FORMAT)}
-        cache.set(cache_key, json.dumps(data))
+        self._set_cache(self.channel.main_tree, last_update=datetime.datetime(1990, 1, 1))
 
-        with patch("contentcuration.views.nodes.getnodedetails_task") as task_mock:
-            url = reverse('get_channel_details', kwargs={"channel_id": self.channel.id})
-            self.get(url)
+        with self._check_details() as details:
+            # check cache was returned
+            self.assertDetailsEqual(details, self.default_details)
             # Check that the outdated cache prompts an asynchronous cache update
             task_mock.enqueue.assert_called_once_with(self.user, node_id=self.channel.main_tree.id)
 
+    @patch("contentcuration.views.nodes.getnodedetails_task")
+    def test_get_channel_details__cached__not_updated__no_enqueue(self, task_mock):
+        # nothing changed,
+        self.channel.main_tree.get_descendants(include_self=False).update(changed=False)
+        self._set_cache(self.channel.main_tree, last_update=datetime.datetime(1990, 1, 1))
+
+        with self._check_details() as details:
+            # check cache was returned
+            self.assertDetailsEqual(details, self.default_details)
+            task_mock.enqueue.assert_not_called()
+
+    @patch("contentcuration.views.nodes.getnodedetails_task")
+    def test_get_channel_details__cached__no_enqueue(self, task_mock):
+        # test last update handling
+        self._set_cache(self.channel.main_tree, last_update=datetime.datetime(2099, 1, 1))
+
+        with self._check_details() as details:
+            # check cache was returned
+            self.assertDetailsEqual(details, self.default_details)
+            task_mock.enqueue.assert_not_called()
+
+    @patch("contentcuration.models.ContentNode.get_details")
+    def test_get_node_details__uncached(self, mock_get_details):
+        mock_get_details.return_value = {
+            "resource_count": 7,
+            "resource_size": 200,
+            "kind_count": {"document": 33, "video": 22}
+        }
+        with self._check_details(node=self.node) as details:
+            self.assertDetailsEqual(details, mock_get_details.return_value)
+
+        mock_get_details.assert_called_once_with(channel=self.channel)
+
+    @patch("contentcuration.views.nodes.getnodedetails_task")
+    def test_get_node_details__cached(self, task_mock):
+        # force the cache to update by adding a very old cache entry. Since Celery tasks run sync in the test suite,
+        # get_channel_details will return an updated cache value rather than generate it async.
+        self._set_cache(self.node, last_update=datetime.datetime(1990, 1, 1))
+
+        with self._check_details(node=self.node) as details:
+            # check cache was returned
+            self.assertDetailsEqual(details, self.default_details)
+            # Check that the outdated cache prompts an asynchronous cache update
+            task_mock.enqueue.assert_called_once_with(self.user, node_id=self.node.pk)
+
+    @patch("contentcuration.views.nodes.getnodedetails_task")
+    def test_get_node_details__cached__not_updated__no_enqueue(self, task_mock):
+        # nothing changed,
+        self.channel.main_tree.get_descendants(include_self=False).update(changed=False)
+        self._set_cache(self.node, last_update=datetime.datetime(1990, 1, 1))
+
+        with self._check_details(node=self.node) as details:
+            # check cache was returned
+            self.assertDetailsEqual(details, self.default_details)
+            task_mock.enqueue.assert_not_called()
+
+    @patch("contentcuration.views.nodes.getnodedetails_task")
+    def test_get_node_details__cached__no_enqueue(self, task_mock):
+        # test last update handling
+        self._set_cache(self.node, last_update=datetime.datetime(2099, 1, 1))
+
+        with self._check_details(node=self.node) as details:
+            # check cache was returned
+            self.assertDetailsEqual(details, self.default_details)
+            task_mock.enqueue.assert_not_called()
+
 
 class ChannelDetailsEndpointTestCase(BaseAPITestCase):
     def test_200_post(self):
diff --git a/contentcuration/contentcuration/tests/views/test_views_internal.py b/contentcuration/contentcuration/tests/views/test_views_internal.py
index 7689bace3a..3a8f50a6d2 100644
--- a/contentcuration/contentcuration/tests/views/test_views_internal.py
+++ b/contentcuration/contentcuration/tests/views/test_views_internal.py
@@ -777,6 +777,23 @@ def test_creates_channel(self):
         except Channel.DoesNotExist:
             self.fail("Channel was not created")
 
+    def test_updates_already_created_channel(self):
+        """
+        Test that it creates a channel with the given id
+        """
+        deleted_channel = channel()
+        deleted_channel.deleted = True
+        deleted_channel.save(actor_id=self.user.id)
+        self.channel_data.update({"name": "Updated name", "id": deleted_channel.id})
+        self.admin_client().post(
+            reverse_lazy("api_create_channel"), data={"channel_data": self.channel_data}, format="json"
+        )
+        try:
+            c = Channel.objects.get(id=self.channel_data["id"])
+            self.assertEqual(c.name, "Updated name")
+        except Channel.DoesNotExist:
+            self.fail("Channel was not created")
+
     def test_creates_cheftree(self):
         """
         Test that it creates a channel with the given id
diff --git a/contentcuration/contentcuration/views/base.py b/contentcuration/contentcuration/views/base.py
index 8ce3966e0c..0c3568dc22 100644
--- a/contentcuration/contentcuration/views/base.py
+++ b/contentcuration/contentcuration/views/base.py
@@ -1,22 +1,17 @@
 import json
-from builtins import str
 from urllib.parse import urlsplit
 
 from django.conf import settings
 from django.contrib.auth.decorators import login_required
 from django.core.cache import cache
-from django.core.exceptions import PermissionDenied
 from django.db.models import Count
-from django.db.models import Exists
 from django.db.models import IntegerField
 from django.db.models import OuterRef
 from django.db.models import Subquery
 from django.db.models import UUIDField
 from django.db.models.functions import Cast
 from django.http import HttpResponse
-from django.http import HttpResponseBadRequest
 from django.http import HttpResponseForbidden
-from django.http import HttpResponseNotFound
 from django.shortcuts import redirect
 from django.shortcuts import render
 from django.urls import is_valid_path
@@ -30,6 +25,7 @@
 from django.views.decorators.http import require_POST
 from django.views.i18n import LANGUAGE_QUERY_PARAMETER
 from django_celery_results.models import TaskResult
+from django_cte import With
 from rest_framework.authentication import BasicAuthentication
 from rest_framework.authentication import SessionAuthentication
 from rest_framework.authentication import TokenAuthentication
@@ -41,13 +37,11 @@
 from rest_framework.response import Response
 
 from .json_dump import json_for_parse_from_data
-from .json_dump import json_for_parse_from_serializer
 from contentcuration.constants import channel_history
 from contentcuration.decorators import browser_is_supported
 from contentcuration.models import Change
 from contentcuration.models import Channel
 from contentcuration.models import ChannelHistory
-from contentcuration.models import ChannelSet
 from contentcuration.models import ContentKind
 from contentcuration.models import CustomTaskMetadata
 from contentcuration.models import DEFAULT_USER_PREFERENCES
@@ -55,7 +49,6 @@
 from contentcuration.models import License
 from contentcuration.serializers import SimplifiedChannelProbeCheckSerializer
 from contentcuration.utils.messages import get_messages
-from contentcuration.viewsets.channelset import PublicChannelSetSerializer
 
 PUBLIC_CHANNELS_CACHE_DURATION = 30  # seconds
 PUBLIC_CHANNELS_CACHE_KEYS = {
@@ -317,7 +310,7 @@ def channel(request, channel_id):
         if channel.deleted:
             channel_error = 'CHANNEL_EDIT_ERROR_CHANNEL_DELETED'
         else:
-            channel_rev = Change.objects.filter(applied=True, channel=channel).values_list("server_rev", flat=True).order_by("-server_rev").first() or 0
+            channel_rev = channel.get_server_rev()
 
     return render(
         request,
diff --git a/contentcuration/contentcuration/views/internal.py b/contentcuration/contentcuration/views/internal.py
index 13eba6376f..f2f268ca1a 100644
--- a/contentcuration/contentcuration/views/internal.py
+++ b/contentcuration/contentcuration/views/internal.py
@@ -519,7 +519,9 @@ def create_channel(channel_data, user):
     if files:
         map_files_to_node(user, channel.chef_tree, files)
     channel.chef_tree.save()
-    channel.save()
+    # If the channel was previously deleted, this save will undelete it
+    # so will require the actor_id to be set
+    channel.save(actor_id=user.id)
 
     # Delete chef tree if it already exists
     if old_chef_tree and old_chef_tree != channel.staging_tree:
diff --git a/contentcuration/contentcuration/views/nodes.py b/contentcuration/contentcuration/views/nodes.py
index a1e924c0c7..635c7b00c1 100644
--- a/contentcuration/contentcuration/views/nodes.py
+++ b/contentcuration/contentcuration/views/nodes.py
@@ -8,6 +8,7 @@
 from django.http import HttpResponse
 from django.http import HttpResponseNotFound
 from django.shortcuts import get_object_or_404
+from django_cte import With
 from rest_framework import status
 from rest_framework.authentication import SessionAuthentication
 from rest_framework.authentication import TokenAuthentication
@@ -36,7 +37,7 @@ def get_channel_details(request, channel_id):
     channel = get_object_or_404(Channel.filter_view_queryset(Channel.objects.all(), request.user), id=channel_id)
     if not channel.main_tree:
         raise Http404
-    data = get_node_details_cached(request.user, channel.main_tree, channel_id=channel_id)
+    data = get_node_details_cached(request.user, channel.main_tree, channel)
     return HttpResponse(json.dumps(data))
 
 
@@ -47,29 +48,41 @@ def get_node_details(request, node_id):
     channel = node.get_channel()
     if channel and not channel.public:
         return HttpResponseNotFound("No topic found for {}".format(node_id))
-    data = get_node_details_cached(request.user, node)
+    data = get_node_details_cached(request.user, node, channel)
     return HttpResponse(json.dumps(data))
 
 
-def get_node_details_cached(user, node, channel_id=None):
+def get_node_details_cached(user, node, channel):
     cached_data = cache.get("details_{}".format(node.node_id))
-    if cached_data:
-        descendants = (
-            node.get_descendants()
-            .prefetch_related("children", "files", "tags")
-            .select_related("license", "language")
-        )
-        channel = node.get_channel()
 
+    if cached_data:
         # If channel is a sushi chef channel, use date created for faster query
         # Otherwise, find the last time anything was updated in the channel
-        last_update = (
-            channel.main_tree.created
-            if channel and channel.ricecooker_version
-            else descendants.filter(changed=True)
-            .aggregate(latest_update=Max("modified"))
-            .get("latest_update")
-        )
+        if channel and channel.ricecooker_version:
+            last_update = channel.main_tree.created
+        else:
+            # The query should never span across multiple trees, so we can filter by tree_id first.
+            # Since the tree_id is indexed, this should be a fast query, and perfect candidate
+            # for the CTE select query.
+            cte = With(
+                ContentNode.objects.filter(tree_id=node.tree_id)
+                .values("id", "modified", "changed", "tree_id", "parent_id", "lft", "rght")
+                .order_by()
+            )
+            last_update_qs = cte.queryset().with_cte(cte).filter(changed=True)
+
+            # If the node is not the root node, the intent is to calculate node details for the
+            # descendants of this node
+            if node.parent_id is not None:
+                # See MPTTModel.get_descendants for details on the lft/rght query
+                last_update_qs = last_update_qs.filter(
+                    lft__gte=node.lft + 1, rght__lte=node.rght - 1
+                )
+            else:
+                # Maintain that query should not 'include_self'
+                last_update_qs = last_update_qs.filter(parent_id__isnull=False)
+
+            last_update = last_update_qs.aggregate(latest_update=Max("modified")).get("latest_update")
 
         if last_update:
             last_cache_update = datetime.strptime(
@@ -80,7 +93,7 @@ def get_node_details_cached(user, node, channel_id=None):
                 getnodedetails_task.enqueue(user, node_id=node.pk)
         return json.loads(cached_data)
 
-    return node.get_details(channel_id=channel_id)
+    return node.get_details(channel=channel)
 
 
 @api_view(["GET"])
diff --git a/contentcuration/contentcuration/viewsets/channel.py b/contentcuration/contentcuration/viewsets/channel.py
index 796f7999e8..5cd9b84104 100644
--- a/contentcuration/contentcuration/viewsets/channel.py
+++ b/contentcuration/contentcuration/viewsets/channel.py
@@ -1,5 +1,4 @@
 import logging
-import uuid
 from functools import reduce
 from operator import or_
 from typing import Dict
@@ -9,13 +8,10 @@
 from django.conf import settings
 from django.db import IntegrityError
 from django.db.models import Exists
-from django.db.models import F
 from django.db.models import OuterRef
 from django.db.models import Q
 from django.db.models import Subquery
-from django.db.models import UUIDField
 from django.db.models import Value
-from django.db.models.functions import Cast
 from django.db.models.functions import Coalesce
 from django.http import HttpResponse
 from django.http import HttpResponseNotFound
@@ -25,7 +21,6 @@
 from django_cte import With
 from django_filters.rest_framework import BooleanFilter
 from django_filters.rest_framework import CharFilter
-from kolibri_public.models import ContentNode as PublicContentNode
 from le_utils.constants import content_kinds
 from le_utils.constants import roles
 from rest_framework import serializers
@@ -744,20 +739,39 @@ def _get_channel_content_languages(self, channel_id, main_tree_id=None) -> List[
         if not channel_id:
             return []
 
+        # determine the tree_id for the channel or from the root node (main_tree_id)
+        tree_id = None
+        if main_tree_id:
+            tree_id = (
+                ContentNode.objects.filter(id=main_tree_id)
+                .values_list("tree_id", flat=True)
+                .first()
+            )
+        elif not main_tree_id:
+            try:
+                tree_id = (
+                    Channel.objects.filter(pk=channel_id)
+                    .values_list("main_tree__tree_id", flat=True)
+                    .first()
+                )
+            except Exception as e:
+                logging.error(str(e))
+                return []
+
         try:
-            ids_to_exclude = [main_tree_id] if main_tree_id else []
-            node_ids_subquery = PublicContentNode.objects.filter(
-                channel_id=uuid.UUID(channel_id),
-            ).values_list("id", flat=True)
-            lang_ids = ContentNode.objects.filter(
+            # performance: use a CTE to select just the tree's nodes, without default MPTT ordering,
+            # then filter against the CTE to get the distinct language IDs
+            cte = With(
+                ContentNode.objects.filter(tree_id=tree_id)
+                .values("id", "language_id")
+                .order_by()
+            )
+            qs = cte.queryset().with_cte(cte).filter(
                 language_id__isnull=False
-            ).annotate(
-                cast_node_id=Cast(F('node_id'), output_field=UUIDField())
-            ).filter(
-                cast_node_id__in=Subquery(node_ids_subquery)
-            ).exclude(
-                id__in=ids_to_exclude
-            ).values_list('language_id', flat=True).distinct()
+            )
+            if main_tree_id:
+                qs = qs.exclude(id=main_tree_id)
+            lang_ids = qs.values_list('language_id', flat=True).distinct()
             unique_lang_ids = list(set(lang_ids))
         except Exception as e:
             logging.error(str(e))
diff --git a/contentcuration/kolibri_public/import_metadata_view.py b/contentcuration/kolibri_public/import_metadata_view.py
index 534596cbb4..100ac870e3 100644
--- a/contentcuration/kolibri_public/import_metadata_view.py
+++ b/contentcuration/kolibri_public/import_metadata_view.py
@@ -14,6 +14,7 @@
 from kolibri_content.constants.schema_versions import MIN_CONTENT_SCHEMA_VERSION  # Use kolibri_content
 from kolibri_public import models  # Use kolibri_public models
 from kolibri_public.views import metadata_cache
+from rest_framework import status
 from rest_framework.generics import get_object_or_404
 from rest_framework.permissions import AllowAny
 from rest_framework.response import Response
@@ -69,6 +70,14 @@ def retrieve(self, request, pk=None):  # noqa: C901
         :return: an object with keys for each content metadata table and a schema_version key
         """
 
+        try:
+            UUID(pk)
+        except ValueError:
+            return Response(
+                {"error": "Invalid UUID format."},
+                status=status.HTTP_400_BAD_REQUEST
+            )
+
         content_schema = request.query_params.get(
             "schema_version", self.default_content_schema
         )
diff --git a/contentcuration/kolibri_public/tests/test_content_app.py b/contentcuration/kolibri_public/tests/test_content_app.py
index 50c4a6a35b..0b6800e0e5 100644
--- a/contentcuration/kolibri_public/tests/test_content_app.py
+++ b/contentcuration/kolibri_public/tests/test_content_app.py
@@ -236,6 +236,17 @@ def _recurse_and_assert(self, data, nodes, recursion_depth=0):
                 )
         return recursion_depth if not recursion_depths else max(recursion_depths)
 
+    def test_contentnode_tree_invalid_uuid(self):
+        invalid_uuid = "8f0a5b9d89795"
+
+        response = self._get(
+            reverse("publiccontentnode_tree-detail", kwargs={"pk": invalid_uuid})
+        )
+
+        self.assertEqual(response.status_code, 400)
+
+        self.assertEqual(response.data["error"], "Invalid UUID format.")
+
     def test_contentnode_tree(self):
         response = self._get(
             reverse("publiccontentnode_tree-detail", kwargs={"pk": self.root.id})
diff --git a/contentcuration/kolibri_public/tests/test_importmetadata_api.py b/contentcuration/kolibri_public/tests/test_importmetadata_api.py
index b9184f6de1..484fa6c382 100644
--- a/contentcuration/kolibri_public/tests/test_importmetadata_api.py
+++ b/contentcuration/kolibri_public/tests/test_importmetadata_api.py
@@ -85,6 +85,17 @@ def test_import_metadata_through_tags(self):
     def test_import_metadata_tags(self):
         self._assert_data(public.ContentTag, content.ContentTag, self.tags)
 
+    def test_import_metadata_invalid_uuid(self):
+        invalid_uuid = "8f0a5b9d89795"
+
+        response = self.client.get(
+            reverse("publicimportmetadata-detail", kwargs={"pk": invalid_uuid})
+        )
+
+        self.assertEqual(response.status_code, 400)
+
+        self.assertEqual(response.data["error"], "Invalid UUID format.")
+
     def test_schema_version_too_low(self):
         response = self.client.get(
             reverse("publicimportmetadata-detail", kwargs={"pk": self.node.id})
diff --git a/contentcuration/kolibri_public/views.py b/contentcuration/kolibri_public/views.py
index 8c66b1993b..faa5588d88 100644
--- a/contentcuration/kolibri_public/views.py
+++ b/contentcuration/kolibri_public/views.py
@@ -10,6 +10,7 @@
 import re
 from collections import OrderedDict
 from functools import reduce
+from uuid import UUID
 
 from django.core.exceptions import ValidationError
 from django.db.models import Exists
@@ -35,6 +36,7 @@
 from kolibri_public.search import get_available_metadata_labels
 from kolibri_public.stopwords import stopwords_set
 from le_utils.constants import content_kinds
+from rest_framework import status
 from rest_framework.permissions import AllowAny
 from rest_framework.response import Response
 
@@ -45,7 +47,6 @@
 from contentcuration.viewsets.base import BaseValuesViewset
 from contentcuration.viewsets.base import ReadOnlyValuesViewset
 
-
 logger = logging.getLogger(__name__)
 
 
@@ -697,8 +698,15 @@ def retrieve(self, request, pk=None):
         :return: an object representing the parent with a pagination object as "children"
         """
 
-        queryset = self.get_tree_queryset(request, pk)
+        try:
+            UUID(pk)
+        except ValueError:
+            return Response(
+                {"error": "Invalid UUID format."},
+                status=status.HTTP_400_BAD_REQUEST
+            )
 
+        queryset = self.get_tree_queryset(request, pk)
         # We explicitly order by lft here, so that the nodes are in tree traversal order, so we can iterate over them and build
         # out our nested representation, being sure that any ancestors have already been processed.
         nodes = self.serialize(queryset.order_by("lft"))