diff --git a/frontend/src/components/Buttons/SubtitleSelectionButton.vue b/frontend/src/components/Buttons/SubtitleSelectionButton.vue
index 2b73f9dc1c2..953a3e00290 100644
--- a/frontend/src/components/Buttons/SubtitleSelectionButton.vue
+++ b/frontend/src/components/Buttons/SubtitleSelectionButton.vue
@@ -79,8 +79,7 @@ export default defineComponent({
   },
   computed: {
     tracks(): PlaybackTrack[] {
-      const subs = this.playbackManager
-        .currentItemParsedSubtitleTracks as PlaybackTrack[];
+      const subs = this.playbackManager.currentItemParsedSubtitleTracks ?? [];
 
       return [
         {
diff --git a/frontend/src/components/Item/ItemMenu.vue b/frontend/src/components/Item/ItemMenu.vue
index aed7e98b239..651735e7369 100644
--- a/frontend/src/components/Item/ItemMenu.vue
+++ b/frontend/src/components/Item/ItemMenu.vue
@@ -226,8 +226,12 @@ function getLibraryOptions(): MenuOption[] {
       action: async (): Promise<void> => {
         if (remote.sdk.api) {
           try {
+            if (!menuProps.item.Id) {
+              throw new Error('Expected item to have id');
+            }
+
             await getItemRefreshApi(remote.sdk.api).refreshItem({
-              itemId: menuProps.item.Id as string,
+              itemId: menuProps.item.Id,
               replaceAllImages: false,
               replaceAllMetadata: false
             });
diff --git a/frontend/src/components/Layout/Carousel/Carousel.vue b/frontend/src/components/Layout/Carousel/Carousel.vue
index 200530e7a2e..a664eb8ea67 100644
--- a/frontend/src/components/Layout/Carousel/Carousel.vue
+++ b/frontend/src/components/Layout/Carousel/Carousel.vue
@@ -97,12 +97,10 @@ function onSlideChange(): void {
     swiperInstance.value?.updateSlides();
   }
 
-  // Propagate events to children
-  emit(
-    'on-slide-change',
-    currentIndex.value,
-    swiperInstance.value as SwiperType
-  );
+  if (swiperInstance.value) {
+    // Propagate events to children
+    emit('on-slide-change', currentIndex.value, swiperInstance.value);
+  }
 }
 /**
  * Handle touch events
@@ -111,7 +109,9 @@ function onTouch(): void {
   isPaused.value = !isPaused.value;
 
   // Propagate events to children
-  emit('on-touch', isPaused.value, swiperInstance.value as SwiperType);
+  if (swiperInstance.value) {
+    emit('on-touch', isPaused.value, swiperInstance.value);
+  }
 }
 
 /**
diff --git a/frontend/src/components/Playback/DraggableQueue.vue b/frontend/src/components/Playback/DraggableQueue.vue
index b011f9f2015..9fde3ab3f03 100644
--- a/frontend/src/components/Playback/DraggableQueue.vue
+++ b/frontend/src/components/Playback/DraggableQueue.vue
@@ -72,9 +72,7 @@ const queue = computed({
   },
   set(newValue: BaseItemDto[]) {
     playbackManager.setNewQueue(
-      newValue.map((item) => {
-        return item.Id as string;
-      })
+      newValue.map((item) => item.Id).filter((id): id is string => !!id)
     );
   }
 });
diff --git a/frontend/src/pages/settings/index.vue b/frontend/src/pages/settings/index.vue
index b802056c698..946e53394b3 100644
--- a/frontend/src/pages/settings/index.vue
+++ b/frontend/src/pages/settings/index.vue
@@ -141,10 +141,10 @@ import { version as clientVersion } from '@/../package.json';
 const { t } = useI18n();
 const route = useRoute();
 const remote = useRemote();
-let systemInfo = {} as SystemInfo;
 
 route.meta.title = t('settings.settings');
 
+let systemInfo: SystemInfo = {};
 if (remote.auth.currentUser?.Policy?.IsAdministrator) {
   systemInfo = (await remote.sdk.newUserApi(getSystemApi).getSystemInfo()).data;
 }
diff --git a/frontend/src/plugins/remote/auth/index.ts b/frontend/src/plugins/remote/auth/index.ts
index 947498f5c44..4887735b072 100644
--- a/frontend/src/plugins/remote/auth/index.ts
+++ b/frontend/src/plugins/remote/auth/index.ts
@@ -93,16 +93,18 @@ class RemotePluginAuth {
       const { data } = await getSystemApi(api).getPublicSystemInfo();
 
       delete data.LocalAddress;
-      serv = data as ServerInfo;
-      serv.PublicAddress = serverUrl;
-      serv.isDefault = isDefault;
+      serv = {
+        ...data,
+        PublicAddress: serverUrl,
+        isDefault: isDefault
+      };
     } catch (error) {
       useSnackbar(i18n.t('login.serverNotFound'), 'error');
-      throw new Error(error as string);
+      throw error;
     }
 
-    const semverMajor = Number.parseInt(serv.Version?.split('.')[0] as string);
-    const semverMinor = Number.parseInt(serv.Version?.split('.')[1] as string);
+    const semverMajor = Number(serv.Version?.split('.')[0]);
+    const semverMinor = Number(serv.Version?.split('.')[1]);
     const isServerVersionSupported =
       semverMajor > 10 || (semverMajor === 10 && semverMinor >= 7);
 
@@ -121,11 +123,15 @@ class RemotePluginAuth {
           state.value.servers.push(serv);
         }
 
-        state.value.currentServerIndex = state.value.servers.indexOf(
-          state.value.servers.find(
-            (serv) => serv.PublicAddress === serverUrl
-          ) as ServerInfo
+        const serverInfo = state.value.servers.find(
+          (serv) => serv.PublicAddress === serverUrl
         );
+        if (!serverInfo) {
+          throw new Error('expected to find server by url');
+        }
+
+        state.value.currentServerIndex =
+          state.value.servers.indexOf(serverInfo);
       }
     } else {
       useSnackbar(i18n.t('login.serverVersionTooLow'), 'error');
@@ -219,7 +225,11 @@ class RemotePluginAuth {
         state.value.users.splice(state.value.users.indexOf(storeUser), 1);
       }
 
-      delete state.value.accessTokens[user.Id as string];
+      if (!user.Id) {
+        throw new Error('expected user to have id');
+      }
+
+      delete state.value.accessTokens[user.Id];
     }
   }
   /**
diff --git a/frontend/src/store/items.ts b/frontend/src/store/items.ts
index 269f8b1eb75..9c075fc02ce 100644
--- a/frontend/src/store/items.ts
+++ b/frontend/src/store/items.ts
@@ -156,7 +156,7 @@ class ItemsStore {
 
     state.value.collectionById[parent.Id] = childIds;
 
-    return this.getChildrenOfParent(parent.Id) as BaseItemDto[];
+    return this.getChildrenOfParent(parent.Id) ?? [];
   };
 
   /**
@@ -196,7 +196,11 @@ class ItemsStore {
     if (childItems.Items) {
       const parent = this.getItemById(parentId);
 
-      return this.addCollection(parent as BaseItemDto, childItems.Items);
+      if (!parent) {
+        throw new Error('expected item to be found');
+      }
+
+      return this.addCollection(parent, childItems.Items);
     }
   };
 
diff --git a/frontend/src/utils/images.ts b/frontend/src/utils/images.ts
index f9e62b13d5d..7b2445dacf8 100644
--- a/frontend/src/utils/images.ts
+++ b/frontend/src/utils/images.ts
@@ -372,7 +372,11 @@ export function getImageInfo(
     itemId = item.Id;
   }
 
-  const url_string = remote.sdk.api?.getItemImageUrl(itemId as string, imgType);
+  if (!itemId) {
+    throw new Error('expected itemId to have been set');
+  }
+
+  const url_string = remote.sdk.api?.getItemImageUrl(itemId, imgType);
 
   if (imgTag && imgType && itemId && url_string) {
     url = new URL(url_string);
diff --git a/frontend/src/utils/supported-features.ts b/frontend/src/utils/supported-features.ts
index 25d5b281fa2..62dc399ba20 100644
--- a/frontend/src/utils/supported-features.ts
+++ b/frontend/src/utils/supported-features.ts
@@ -34,17 +34,15 @@ function supportsFullscreen(): boolean {
   }
 
   const element = document.documentElement;
+  const video = document.createElement('video');
 
   return !!(
     element.requestFullscreen ||
-    // @ts-expect-error -- Non-standard property
-    element.mozRequestFullScreen ||
-    // @ts-expect-error -- Non-standard property
-    element.webkitRequestFullscreen ||
-    // @ts-expect-error -- Non-standard property
-    element.msRequestFullscreen ||
-    // @ts-expect-error -- Non-standard property
-    document.createElement('video').webkitEnterFullscreen
+    // check properties that are not recorded on the element type
+    ('mozRequestFullScreen' in element && element.mozRequestFullScreen) ||
+    ('webkitRequestFullscreen' in element && element.webkitRequestFullscreen) ||
+    ('msRequestFullscreen' in element && element.msRequestFullscreen) ||
+    ('webkitEnterFullscreen' in video && video.webkitEnterFullscreen)
   );
 }
 
@@ -52,13 +50,11 @@ const video = document.createElement('video');
 
 if (
   // Check non-standard Safari PiP support
-  // @ts-expect-error - Non-standard functions doesn't have typings
-  (typeof video.webkitSupportsPresentationMode === 'function' &&
-    // @ts-expect-error - Non-standard functions doesn't have typings
+  ('webkitSupportsPresentationMode' in video &&
+    typeof video.webkitSupportsPresentationMode === 'function' &&
     video.webkitSupportsPresentationMode('picture-in-picture') &&
-    // @ts-expect-error - Non-standard functions doesn't have typings
-    typeof video.webkitSetPresentationMode === 'function') ||
-  // Check standard PiP support
+    'webkitSetPresentationMode' in video &&
+    typeof video.webkitSetPresentationMode) ||
   document.pictureInPictureEnabled
 ) {
   supportedFeatures.pictureInPicture = true;