diff --git a/frontend/src/app/core/apiv3/endpoints/queries/apiv3-queries-paths.ts b/frontend/src/app/core/apiv3/endpoints/queries/apiv3-queries-paths.ts
index 71080464e1c1..f4bf59173663 100644
--- a/frontend/src/app/core/apiv3/endpoints/queries/apiv3-queries-paths.ts
+++ b/frontend/src/app/core/apiv3/endpoints/queries/apiv3-queries-paths.ts
@@ -38,6 +38,7 @@ import { CollectionResource } from 'core-app/features/hal/resources/collection-r
 import { ApiV3ListParameters, listParamsString } from 'core-app/core/apiv3/paths/apiv3-list-resource.interface';
 import { QueryFiltersService } from 'core-app/features/work-packages/components/wp-query/query-filters.service';
 import { HalPayloadHelper } from 'core-app/features/hal/schemas/hal-payload.helper';
+import { HTTPClientParamMap } from 'core-app/features/hal/http/http.interfaces';
 
 export class ApiV3QueriesPaths extends ApiV3ResourceCollection<QueryResource, ApiV3QueryPaths> {
   @LazyInject() private queryFilters:QueryFiltersService;
@@ -89,7 +90,7 @@ export class ApiV3QueriesPaths extends ApiV3ResourceCollection<QueryResource, Ap
 
     return this
       .halResourceService
-      .get<QueryResource>(path, queryData);
+      .get<QueryResource>(path, queryData as HTTPClientParamMap);
   }
 
   /**
@@ -101,7 +102,7 @@ export class ApiV3QueriesPaths extends ApiV3ResourceCollection<QueryResource, Ap
     return this.halResourceService
       .get<QueryResource>(
         this.default.path,
-        params,
+        params as HTTPClientParamMap,
       );
   }
 
diff --git a/frontend/src/app/core/apiv3/endpoints/queries/apiv3-query-paths.ts b/frontend/src/app/core/apiv3/endpoints/queries/apiv3-query-paths.ts
index e2fd8fb6b705..e8df6622aa5b 100644
--- a/frontend/src/app/core/apiv3/endpoints/queries/apiv3-query-paths.ts
+++ b/frontend/src/app/core/apiv3/endpoints/queries/apiv3-query-paths.ts
@@ -36,6 +36,7 @@ import { LazyInject } from 'core-app/shared/helpers/angular/lazy-inject.decorato
 import { QueryFiltersService } from 'core-app/features/work-packages/components/wp-query/query-filters.service';
 import { HalPayloadHelper } from 'core-app/features/hal/schemas/hal-payload.helper';
 import { PaginationObject } from 'core-app/shared/components/table-pagination/pagination-service';
+import { HTTPClientParamMap } from 'core-app/features/hal/http/http.interfaces';
 
 export class ApiV3QueryPaths extends ApiV3GettableResource<QueryResource> {
   @LazyInject() private queryFilters:QueryFiltersService;
@@ -52,7 +53,7 @@ export class ApiV3QueryPaths extends ApiV3GettableResource<QueryResource> {
    */
   public parameterised(params:object):Observable<QueryResource> {
     return this.halResourceService
-      .get<QueryResource>(this.path, params);
+      .get<QueryResource>(this.path, params as HTTPClientParamMap);
   }
 
   /**
diff --git a/frontend/src/app/core/model-auth/model-auth.service.ts b/frontend/src/app/core/model-auth/model-auth.service.ts
index 0333565d8d0d..3a79ea3f3589 100644
--- a/frontend/src/app/core/model-auth/model-auth.service.ts
+++ b/frontend/src/app/core/model-auth/model-auth.service.ts
@@ -31,7 +31,7 @@ import { input } from '@openproject/reactivestates';
 import { Observable } from 'rxjs';
 import { takeUntil } from 'rxjs/operators';
 
-export type ModelLinks = Record<string, any>;
+export type ModelLinks = Record<string, unknown>;
 export type ModelLinksHash = Record<string, ModelLinks>;
 
 @Injectable({ providedIn: 'root' })
@@ -46,7 +46,7 @@ export class AuthorisationService {
     });
   }
 
-  public observeUntil(unsubscribe:Observable<any>) {
+  public observeUntil(unsubscribe:Observable<unknown>) {
     return this.links.values$().pipe(takeUntil(unsubscribe));
   }
 
diff --git a/frontend/src/app/core/schemas/schema-cache.service.ts b/frontend/src/app/core/schemas/schema-cache.service.ts
index 973413d76e70..91bca36e6af8 100644
--- a/frontend/src/app/core/schemas/schema-cache.service.ts
+++ b/frontend/src/app/core/schemas/schema-cache.service.ts
@@ -129,7 +129,7 @@ export class SchemaCacheService extends StateCacheService<SchemaResource> {
       );
   }
 
-  protected loadAll(hrefs:string[]):Promise<unknown|undefined> {
+  protected loadAll(hrefs:string[]):Promise<unknown> {
     return Promise.all(hrefs.map((href) => this.load(href)));
   }
 
diff --git a/frontend/src/app/core/state/capabilities/capabilities.service.ts b/frontend/src/app/core/state/capabilities/capabilities.service.ts
index 6e136fe4ee90..64f3f5ecf4d6 100644
--- a/frontend/src/app/core/state/capabilities/capabilities.service.ts
+++ b/frontend/src/app/core/state/capabilities/capabilities.service.ts
@@ -40,6 +40,7 @@ import {
   ResourceStore,
   ResourceStoreService,
 } from 'core-app/core/state/resource-store.service';
+import { HttpErrorResponse } from '@angular/common/http';
 
 @Injectable()
 export class CapabilitiesResourceService extends ResourceStoreService<ICapability> {
@@ -59,7 +60,7 @@ export class CapabilitiesResourceService extends ResourceStoreService<ICapabilit
     return this
       .fetchCollection(params)
       .pipe(
-        catchError((error) => {
+        catchError((error:HttpErrorResponse) => {
           this.toastService.addError(error);
           throw error;
         }),
diff --git a/frontend/src/app/core/states/states.service.ts b/frontend/src/app/core/states/states.service.ts
index 8e42af9ef35d..de68c9f468fd 100644
--- a/frontend/src/app/core/states/states.service.ts
+++ b/frontend/src/app/core/states/states.service.ts
@@ -93,7 +93,7 @@ export class States extends StatesGroup {
   additional:Record<string, MultiInputState<unknown>> = {};
 
   forType<T>(stateName:string):MultiInputState<T> {
-    let state = (this as any)[stateName] || this.additional[stateName];
+    let state = (this as unknown as Record<string, MultiInputState<T>|undefined>)[stateName] ?? this.additional[stateName] as MultiInputState<T>|undefined;
 
     if (!state) {
       state = this.additional[stateName] = multiInput<T>();
diff --git a/frontend/src/app/features/admin/editable-query-props/editable-query-props.component.ts b/frontend/src/app/features/admin/editable-query-props/editable-query-props.component.ts
index 82caea3d7282..7bbbb409d78a 100644
--- a/frontend/src/app/features/admin/editable-query-props/editable-query-props.component.ts
+++ b/frontend/src/app/features/admin/editable-query-props/editable-query-props.component.ts
@@ -76,7 +76,7 @@ export class EditableQueryPropsComponent implements OnInit {
         // eslint-disable-next-line @typescript-eslint/no-unsafe-return
         return JSON.parse(this.queryProps);
       } catch (e) {
-        console.error(`Failed to parse query props from ${this.queryProps}: ${e}`);
+        console.error(`Failed to parse query props from ${this.queryProps}: ${String(e)}`);
         return {};
       }
     })();
diff --git a/frontend/src/app/features/bim/bcf/api/bcf-api-request.service.ts b/frontend/src/app/features/bim/bcf/api/bcf-api-request.service.ts
index 5cdf27f3f69f..3c52b59043b7 100644
--- a/frontend/src/app/features/bim/bcf/api/bcf-api-request.service.ts
+++ b/frontend/src/app/features/bim/bcf/api/bcf-api-request.service.ts
@@ -70,7 +70,7 @@ export class BcfApiRequestService<T> {
       responseType: 'json',
     };
 
-    return this._request('get', path, config);
+    return this.sendRequest('get', path, config);
   }
 
   /**
@@ -81,11 +81,11 @@ export class BcfApiRequestService<T> {
    * @param data Request payload (URL params for get, JSON payload otherwise)
    * @param headers Request headers
    */
-  public request(method:HTTPSupportedMethods, path:string, data:HTTPClientParamMap = {}, headers:HTTPClientHeaders = {}):Observable<T> {
+  public request(method:HTTPSupportedMethods, path:string, data:unknown = {}, headers:HTTPClientHeaders = {}):Observable<T> {
     // HttpClient requires us to create HttpParams instead of passing data for get
     // so forward to that method instead.
     if (method === 'get') {
-      return this.get(path, data, headers);
+      return this.get(path, data as HTTPClientParamMap, headers);
     }
 
     const config:HTTPClientOptions = {
@@ -95,7 +95,7 @@ export class BcfApiRequestService<T> {
       responseType: 'json',
     };
 
-    return this._request(method, path, config);
+    return this.sendRequest(method, path, config);
   }
 
   /**
@@ -107,12 +107,12 @@ export class BcfApiRequestService<T> {
    *
    * @private
    */
-  private _request(method:HTTPSupportedMethods, path:string, config:HTTPClientOptions):Observable<T> {
+  private sendRequest(method:HTTPSupportedMethods, path:string, config:HTTPClientOptions):Observable<T> {
     return this
       .http
       .request<T>(method, path, config)
       .pipe(
-        map((response:any) => this.deserialize(response)),
+        map((response) => this.deserialize(response)),
         catchError((error:HttpErrorResponse) => {
           console.error(`Failed to ${method} ${path}: ${error.name}`);
           return throwError(error);
@@ -124,11 +124,11 @@ export class BcfApiRequestService<T> {
    * Deserialize the JSON data into the mapped resource class, if given.
    * @param data JSON API response.
    */
-  protected deserialize(data:any):T {
+  protected deserialize(data:unknown):T {
     if (this.resourceClass) {
       const serializer = new TypedJSON(this.resourceClass);
-      return serializer.parse(data)!;
+      return serializer.parse(data) as T;
     }
-    return data;
+    return data as T;
   }
 }
diff --git a/frontend/src/app/features/bim/bcf/api/bcf-api.service.ts b/frontend/src/app/features/bim/bcf/api/bcf-api.service.ts
index 21cc945d65e1..0be855467895 100644
--- a/frontend/src/app/features/bim/bcf/api/bcf-api.service.ts
+++ b/frontend/src/app/features/bim/bcf/api/bcf-api.service.ts
@@ -58,22 +58,22 @@ export class BcfApiService {
       .split('/');
 
     // Try to find a target collection or resource
-    let current:any = this;
+    let current = this as object;
 
     for (const pathOrId of parts) {
       if (pathOrId in current) {
         // Current has a member named like this URL part
         // descend into it
-        current = current[pathOrId];
+        current = (current as Record<string, object>)[pathOrId];
       } else if (current instanceof BcfResourceCollectionPath) {
         // Otherwise, assume we're looking for an ID
-        current = current.id(pathOrId);
+        current = current.id(pathOrId) as object;
       } else {
         // Otherwise, return the current
         break;
       }
     }
 
-    return current === this ? undefined : current;
+    return current === this ? undefined : current as T;
   }
 }
diff --git a/frontend/src/app/features/bim/bcf/api/topics/bcf-topic.resource.ts b/frontend/src/app/features/bim/bcf/api/topics/bcf-topic.resource.ts
index 8608b72334f9..61d49454cd5c 100644
--- a/frontend/src/app/features/bim/bcf/api/topics/bcf-topic.resource.ts
+++ b/frontend/src/app/features/bim/bcf/api/topics/bcf-topic.resource.ts
@@ -64,13 +64,13 @@ export class BcfTopicResource {
   @jsonArrayMember(String)
   labels:string[];
 
-  @jsonMember({ deserializer: (value) => moment(value), serializer: (timestamp:Moment) => timestamp.toISOString() })
+  @jsonMember({ deserializer: (value:string) => moment(value), serializer: (timestamp:Moment) => timestamp.toISOString() })
   creation_date:Moment;
 
   @jsonMember(String)
   creation_author:string;
 
-  @jsonMember({ deserializer: (value) => moment(value), serializer: (timestamp:Moment) => timestamp.toISOString() })
+  @jsonMember({ deserializer: (value:string) => moment(value), serializer: (timestamp:Moment) => timestamp.toISOString() })
   modified_date:Moment;
 
   @jsonMember(String, { preserveNull: true })
@@ -86,7 +86,7 @@ export class BcfTopicResource {
   description:string;
 
   @jsonMember({
-    deserializer: (value) => moment(value),
+    deserializer: (value:string) => moment(value),
     serializer: (timestamp:Moment) => timestamp.format('YYYY-MM-DD'),
   })
   due_date:Moment;
diff --git a/frontend/src/app/features/bim/bcf/api/topics/bcf-viewpoint-collection.paths.ts b/frontend/src/app/features/bim/bcf/api/topics/bcf-viewpoint-collection.paths.ts
index 4880615e6fcb..b51de3e4df12 100644
--- a/frontend/src/app/features/bim/bcf/api/topics/bcf-viewpoint-collection.paths.ts
+++ b/frontend/src/app/features/bim/bcf/api/topics/bcf-viewpoint-collection.paths.ts
@@ -50,7 +50,7 @@ export class BcfTopicCollectionPath extends BcfResourceCollectionPath<BcfTopicPa
   /**
    * Create a topic from its to-be-associated work package
    */
-  post(payload:any):Observable<BcfTopicResource> {
+  post(payload:unknown):Observable<BcfTopicResource> {
     return this
       .bcfTopicService
       .request(
diff --git a/frontend/src/app/features/bim/bcf/bcf-wp-attribute-group/bcf-wp-attribute-group.component.ts b/frontend/src/app/features/bim/bcf/bcf-wp-attribute-group/bcf-wp-attribute-group.component.ts
index 241968ad46ab..893e22f19cbc 100644
--- a/frontend/src/app/features/bim/bcf/bcf-wp-attribute-group/bcf-wp-attribute-group.component.ts
+++ b/frontend/src/app/features/bim/bcf/bcf-wp-attribute-group/bcf-wp-attribute-group.component.ts
@@ -29,7 +29,7 @@
 import { AfterViewInit, ChangeDetectionStrategy, ChangeDetectorRef, Component, Input, OnDestroy, OnInit, ViewChild, inject } from '@angular/core';
 import { UrlParamsService } from 'core-app/core/navigation/url-params.service';
 import { WorkPackageResource } from 'core-app/features/hal/resources/work-package-resource';
-import { NgxGalleryComponent, NgxGalleryOptions } from '@kolkov/ngx-gallery';
+import { NgxGalleryComponent, NgxGalleryImage, NgxGalleryOptions } from '@kolkov/ngx-gallery';
 import { HalLink } from 'core-app/features/hal/hal-link/hal-link';
 import idFromLink from 'core-app/features/hal/helpers/id-from-link';
 import { I18nService } from 'core-app/core/i18n/i18n.service';
@@ -135,7 +135,7 @@ export class BcfWpAttributeGroupComponent extends UntilDestroyedMixin implements
 
   viewpoints:BcfViewpointItem[] = [];
 
-  galleryImages:any[] = [];
+  galleryImages:NgxGalleryImage[] = [];
 
   // Store whether viewing is allowed
   viewAllowed = false;
@@ -279,7 +279,7 @@ export class BcfWpAttributeGroupComponent extends UntilDestroyedMixin implements
     return [
       {
         icon: 'icon-view-model',
-        onClick: (evt:any, index:number) => {
+        onClick: (evt:Event, index:number) => {
           this.showViewpoint(this.workPackage, index);
           this.gallery.preview.close();
         },
@@ -287,7 +287,7 @@ export class BcfWpAttributeGroupComponent extends UntilDestroyedMixin implements
       },
       {
         icon: 'icon-delete',
-        onClick: (evt:any, index:number) => this.deleteViewpoint(this.workPackage, index),
+        onClick: (evt:Event, index:number) => this.deleteViewpoint(this.workPackage, index),
         titleText: this.text.delete_viewpoint,
       },
     ];
diff --git a/frontend/src/app/features/bim/ifc_models/toolbar/import-export-bcf/bcf-export-button.component.ts b/frontend/src/app/features/bim/ifc_models/toolbar/import-export-bcf/bcf-export-button.component.ts
index bcaf68a03bd9..0dadc3264f39 100644
--- a/frontend/src/app/features/bim/ifc_models/toolbar/import-export-bcf/bcf-export-button.component.ts
+++ b/frontend/src/app/features/bim/ifc_models/toolbar/import-export-bcf/bcf-export-button.component.ts
@@ -96,7 +96,7 @@ export class BcfExportButtonComponent extends UntilDestroyedMixin implements OnI
       });
   }
 
-  public showDelayedExport(event:any) {
+  public showDelayedExport(event:Event) {
     this.requestExport(this.exportLink);
 
     event.preventDefault();
diff --git a/frontend/src/app/features/boards/board/add-list-modal/add-list-modal.component.ts b/frontend/src/app/features/boards/board/add-list-modal/add-list-modal.component.ts
index 61a34befe334..89af46d9ef82 100644
--- a/frontend/src/app/features/boards/board/add-list-modal/add-list-modal.component.ts
+++ b/frontend/src/app/features/boards/board/add-list-modal/add-list-modal.component.ts
@@ -97,7 +97,7 @@ export class AddListModalComponent extends OpModalComponent implements OnInit {
 
   public warningText:string|undefined;
 
-  public text:any = {
+  public text = {
     title: this.I18n.t('js.boards.add_list'),
     button_add: this.I18n.t('js.button_add'),
     button_create: this.I18n.t('js.button_create'),
@@ -118,7 +118,7 @@ export class AddListModalComponent extends OpModalComponent implements OnInit {
 
   ngOnInit() {
     super.ngOnInit();
-    this.board = this.locals.board;
+    this.board = this.locals.board as Board;
     this.active = new Set(this.locals.active as string[]);
     this.actionService = this.boardActions.get(this.board.actionAttribute!);
     this.autocompleterOptions.resource = this.actionService.resourceName.toLowerCase();
@@ -162,15 +162,14 @@ export class AddListModalComponent extends OpModalComponent implements OnInit {
   }
 
   private getVersionPayload(name:string) {
-    const payload:any = {};
-    payload.name = name;
-    payload._links = {
-      definingProject: {
-        href: this.apiV3Service.projects.id(this.currentProject.id!).path,
+    return {
+      name,
+      _links: {
+        definingProject: {
+          href: this.apiV3Service.projects.id(this.currentProject.id!).path,
+        },
       },
     };
-
-    return payload;
   }
 
   private warnIfNoOptions(values:unknown[]) {
diff --git a/frontend/src/app/features/boards/board/board-list/board-list.component.ts b/frontend/src/app/features/boards/board/board-list/board-list.component.ts
index 3b8162fe8d05..ea2f89520ccb 100644
--- a/frontend/src/app/features/boards/board/board-list/board-list.component.ts
+++ b/frontend/src/app/features/boards/board/board-list/board-list.component.ts
@@ -95,6 +95,7 @@ import { firstValueFrom } from 'rxjs';
 import { WorkPackageIsolatedQuerySpaceDirective } from 'core-app/features/work-packages/directives/query-space/wp-isolated-query-space.directive';
 import { CurrentProjectService } from 'core-app/core/current-project/current-project.service';
 import { PathHelperService } from 'core-app/core/path-helper/path-helper.service';
+import { HTTPClientParamMap } from 'core-app/features/hal/http/http.interfaces';
 
 export interface DisabledButtonPlaceholder {
   text:string;
@@ -176,7 +177,7 @@ export class BoardListComponent extends AbstractWidgetComponent implements OnIni
 
   private canAdd = firstValueFrom(this.wpInlineCreate.canAdd);
 
-  public columnsQueryProps:any;
+  public columnsQueryProps:HTTPClientParamMap;
 
   public get text() {
     return {
@@ -480,7 +481,7 @@ export class BoardListComponent extends AbstractWidgetComponent implements OnIni
     const existingFilters = (this.resource.options.filters || []) as ApiV3Filter[];
 
     const newFilters = existingFilters.concat(filters);
-    const newColumnsQueryProps:any = {
+    const newColumnsQueryProps:HTTPClientParamMap = {
       'columns[]': ['id', 'subject'],
       showHierarchies: false,
       pageSize: 500,
diff --git a/frontend/src/app/features/boards/board/board-partitioned-page/board-list-container.component.ts b/frontend/src/app/features/boards/board/board-partitioned-page/board-list-container.component.ts
index 51e74727d837..0f7aa2cc6cbe 100644
--- a/frontend/src/app/features/boards/board/board-partitioned-page/board-list-container.component.ts
+++ b/frontend/src/app/features/boards/board/board-partitioned-page/board-list-container.component.ts
@@ -183,12 +183,12 @@ export class BoardListContainerComponent extends UntilDestroyedMixin implements
     this.saveBoard(board);
   }
 
-  addList(board:Board):any {
+  addList(board:Board):Promise<unknown>|undefined {
     if (board.isFree) {
       return this.BoardList
         .addFreeQuery(board, { name: this.text.unnamedList })
         .then((board) => this.Boards.save(board).toPromise())
-        .catch((error) => this.showError(error));
+        .catch((error) => this.showError(error as string));
     }
     const active = this.getActionFiltersFromWidget(board);
     this.opModalService.show(
@@ -196,6 +196,7 @@ export class BoardListContainerComponent extends UntilDestroyedMixin implements
       this.injector,
       { board, active },
     );
+    return undefined;
   }
 
   changeVisibilityOfList(board:Board, boardWidget:GridWidgetResource, visible:boolean) {
diff --git a/frontend/src/app/features/boards/board/board-partitioned-page/board-partitioned-page.component.ts b/frontend/src/app/features/boards/board/board-partitioned-page/board-partitioned-page.component.ts
index 636492f6b2d1..2cad74ec1979 100644
--- a/frontend/src/app/features/boards/board/board-partitioned-page/board-partitioned-page.component.ts
+++ b/frontend/src/app/features/boards/board/board-partitioned-page/board-partitioned-page.component.ts
@@ -58,6 +58,7 @@ import { SubmenuService } from 'core-app/core/main-menu/submenu.service';
 import { PathHelperService } from 'core-app/core/path-helper/path-helper.service';
 import { CurrentProjectService } from 'core-app/core/current-project/current-project.service';
 import * as Turbo from '@hotwired/turbo';
+import { ApiV3Filter } from 'core-app/shared/helpers/api-v3/api-v3-filter-builder';
 
 export function boardCardViewHandlerFactory(injector:Injector) {
   return new CardViewHandlerRegistry(injector);
@@ -189,7 +190,7 @@ export class BoardPartitionedPageComponent extends UntilDestroyedMixin implement
         this.editable = board.editable;
         this.selectedTitle = board.name;
         this.titleService.setFirstPart(board.name);
-        this.boardFilters.filters.putValue(queryProps ? JSON.parse(queryProps) : board.filters);
+        this.boardFilters.filters.putValue(queryProps ? JSON.parse(queryProps) as ApiV3Filter[] : board.filters);
 
         this.cdRef.detectChanges();
       });
diff --git a/frontend/src/app/features/boards/board/board.service.ts b/frontend/src/app/features/boards/board/board.service.ts
index d84b0c26034d..845028103d15 100644
--- a/frontend/src/app/features/boards/board/board.service.ts
+++ b/frontend/src/app/features/boards/board/board.service.ts
@@ -51,7 +51,7 @@ export class BoardService {
   private text = {
     unnamed_board: this.I18n.t('js.boards.label_unnamed_board'),
     action_board: (attr:string) => this.I18n.t('js.boards.board_type.action_by_attribute',
-      { attribute: this.I18n.t(`js.boards.board_type.action_type.${attr}`) }),
+      { attribute: this.I18n.t<string>(`js.boards.board_type.action_type.${attr}`) }),
     unnamed_list: this.I18n.t('js.boards.label_unnamed_list'),
   };
 
diff --git a/frontend/src/app/features/boards/board/configuration-modal/tabs/highlighting-tab.component.ts b/frontend/src/app/features/boards/board/configuration-modal/tabs/highlighting-tab.component.ts
index 6af41e24b0a7..fa0d459955a6 100644
--- a/frontend/src/app/features/boards/board/configuration-modal/tabs/highlighting-tab.component.ts
+++ b/frontend/src/app/features/boards/board/configuration-modal/tabs/highlighting-tab.component.ts
@@ -73,7 +73,7 @@ export class BoardHighlightingTabComponent implements TabComponent, OnInit {
   }
 
   ngOnInit() {
-    this.board = this.locals.board;
+    this.board = this.locals.board as Board;
     this.highlightingMode = this.board.highlightingMode;
     this.updateMode(this.highlightingMode);
   }
diff --git a/frontend/src/app/features/hal/http/http.interfaces.ts b/frontend/src/app/features/hal/http/http.interfaces.ts
index c0432974a924..bd760862eb56 100644
--- a/frontend/src/app/features/hal/http/http.interfaces.ts
+++ b/frontend/src/app/features/hal/http/http.interfaces.ts
@@ -40,6 +40,7 @@ export interface HTTPClientOptions {
   responseType:'json';
 }
 
-export type HTTPClientParamMap = Record<string, any>;
-export type HTTPClientHeaders = HttpHeaders|HTTPClientParamMap;
+export type HTTPClientParamValue = string|number|boolean|readonly (string|number|boolean)[];
+export type HTTPClientParamMap = Record<string, HTTPClientParamValue>;
+export type HTTPClientHeaders = HttpHeaders|Record<string, string|string[]>;
 export type HTTPClientParams = HttpParams|HTTPClientParamMap;
diff --git a/frontend/src/app/features/user-preferences/state/user-preferences.service.ts b/frontend/src/app/features/user-preferences/state/user-preferences.service.ts
index 32bd94ce8b76..5b74b9b2c4c7 100644
--- a/frontend/src/app/features/user-preferences/state/user-preferences.service.ts
+++ b/frontend/src/app/features/user-preferences/state/user-preferences.service.ts
@@ -34,6 +34,7 @@ import { I18nService } from 'core-app/core/i18n/i18n.service';
 import { IUserPreference } from 'core-app/features/user-preferences/state/user-preferences.model';
 import { UserPreferencesStore } from 'core-app/features/user-preferences/state/user-preferences.store';
 import { UserPreferencesQuery } from 'core-app/features/user-preferences/state/user-preferences.query';
+import { HttpErrorResponse } from '@angular/common/http';
 
 @Injectable({ providedIn: 'root' })
 export class UserPreferencesService {
@@ -50,8 +51,8 @@ export class UserPreferencesService {
     this.preferenceAPI(user)
       .get()
       .subscribe(
-        (prefs) => this.store.update(prefs),
-        (error) => this.toastService.addError(error),
+        (prefs) => { this.store.update(prefs); },
+        (error:HttpErrorResponse) => this.toastService.addError(error),
       )
       .add(
         () => this.store.setLoading(false),
@@ -68,7 +69,7 @@ export class UserPreferencesService {
           this.store.update(prefs);
           this.toastService.addSuccess(this.I18n.t('js.notice_successful_update'));
         },
-        (error) => this.toastService.addError(error),
+        (error:HttpErrorResponse) => this.toastService.addError(error),
       )
       .add(() => this.store.setLoading(false));
   }
diff --git a/frontend/src/app/shared/components/autocompleter/create-autocompleter/create-autocompleter.component.ts b/frontend/src/app/shared/components/autocompleter/create-autocompleter/create-autocompleter.component.ts
index 08077650eb73..486f26989afb 100644
--- a/frontend/src/app/shared/components/autocompleter/create-autocompleter/create-autocompleter.component.ts
+++ b/frontend/src/app/shared/components/autocompleter/create-autocompleter/create-autocompleter.component.ts
@@ -62,7 +62,7 @@ export class CreateAutocompleterComponent extends UntilDestroyedMixin implements
 
   @Input() public resource:HalResource;
 
-  @Input() public model:any;
+  @Input() public model:unknown;
 
   @Input() public required = false;
 
diff --git a/frontend/src/app/shared/components/autocompleter/version-autocompleter/version-autocompleter.component.ts b/frontend/src/app/shared/components/autocompleter/version-autocompleter/version-autocompleter.component.ts
index 15ebaaf7c151..486cfc94429d 100644
--- a/frontend/src/app/shared/components/autocompleter/version-autocompleter/version-autocompleter.component.ts
+++ b/frontend/src/app/shared/components/autocompleter/version-autocompleter/version-autocompleter.component.ts
@@ -107,14 +107,13 @@ export class VersionAutocompleterComponent extends CreateAutocompleterComponent
   }
 
   private getVersionPayload(name:string) {
-    const payload:any = {};
-    payload.name = name;
-    payload._links = {
-      definingProject: {
-        href: this.apiV3Service.projects.id(this.currentProject.id!).path,
+    return {
+      name,
+      _links: {
+        definingProject: {
+          href: this.apiV3Service.projects.id(this.currentProject.id!).path,
+        },
       },
     };
-
-    return payload;
   }
 }
diff --git a/frontend/src/app/shared/components/date/op-date-time.component.ts b/frontend/src/app/shared/components/date/op-date-time.component.ts
index 7052772da6bf..3958ed87e67e 100644
--- a/frontend/src/app/shared/components/date/op-date-time.component.ts
+++ b/frontend/src/app/shared/components/date/op-date-time.component.ts
@@ -47,11 +47,11 @@ import { TimezoneService } from 'core-app/core/datetime/timezone.service';
 export class OpDateTimeComponent implements OnInit {
   readonly timezoneService = inject(TimezoneService);
 
-  @Input() dateTimeValue:any;
+  @Input() dateTimeValue:string;
 
-  public date:any;
+  public date:string;
 
-  public time:any;
+  public time:string;
 
   ngOnInit() {
     const c = this.timezoneService.formattedDatetimeComponents(this.dateTimeValue);
diff --git a/frontend/src/app/shared/components/datepicker/wp-date-picker-modal/wp-date-picker.modal.ts b/frontend/src/app/shared/components/datepicker/wp-date-picker-modal/wp-date-picker.modal.ts
index 56149d1fd101..ca64bcd32573 100644
--- a/frontend/src/app/shared/components/datepicker/wp-date-picker-modal/wp-date-picker.modal.ts
+++ b/frontend/src/app/shared/components/datepicker/wp-date-picker-modal/wp-date-picker.modal.ts
@@ -31,6 +31,14 @@ import { ChangeDetectionStrategy, Component, OnInit, inject } from '@angular/cor
 import { OpModalComponent } from 'core-app/shared/components/modal/modal.component';
 import { PathHelperService } from 'core-app/core/path-helper/path-helper.service';
 
+interface DatePickerModalResource {
+  id:string;
+  startDate:string|null;
+  dueDate:string|null;
+  duration:string|null;
+  includeNonWorkingDays:boolean|null;
+}
+
 @Component({
   templateUrl: './wp-date-picker.modal.html',
   changeDetection: ChangeDetectionStrategy.OnPush,
@@ -75,43 +83,33 @@ export class OpWpDatePickerModalComponent extends OpModalComponent implements On
   }
 
   public updateFrameSrc():void {
+    const resource = this.locals.resource as DatePickerModalResource;
     const url = new URL(
-      // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
-      this.pathHelper.workPackageDatepickerDialogContentPath(this.locals.resource.id as string),
+      this.pathHelper.workPackageDatepickerDialogContentPath(resource.id),
       window.location.origin,
     );
 
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
-    url.searchParams.set('field', this.locals.name);
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-argument,@typescript-eslint/no-unsafe-member-access
-    url.searchParams.set('work_package[initial][start_date]', this.nullAsEmptyStringFormatter(this.locals.resource.startDate));
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-argument,@typescript-eslint/no-unsafe-member-access
-    url.searchParams.set('work_package[initial][due_date]', this.nullAsEmptyStringFormatter(this.locals.resource.dueDate));
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-argument,@typescript-eslint/no-unsafe-member-access
-    url.searchParams.set('work_package[initial][duration]', this.nullAsEmptyStringFormatter(this.locals.resource.duration));
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access, @typescript-eslint/no-unsafe-argument
-    url.searchParams.set('work_package[initial][ignore_non_working_days]', this.nullAsEmptyStringFormatter(this.locals.resource.includeNonWorkingDays));
-
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-argument,@typescript-eslint/no-unsafe-member-access
-    url.searchParams.set('work_package[start_date]', this.nullAsEmptyStringFormatter(this.locals.resource.startDate));
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-argument,@typescript-eslint/no-unsafe-member-access
-    url.searchParams.set('work_package[due_date]', this.nullAsEmptyStringFormatter(this.locals.resource.dueDate));
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-argument,@typescript-eslint/no-unsafe-member-access
-    url.searchParams.set('work_package[duration]', this.nullAsEmptyStringFormatter(this.locals.resource.duration));
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access, @typescript-eslint/no-unsafe-argument
-    url.searchParams.set('work_package[ignore_non_working_days]', this.nullAsEmptyStringFormatter(this.locals.resource.includeNonWorkingDays));
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
-    if (this.locals.resource?.id === 'new' && this.locals.resource.startDate) {
+    url.searchParams.set('field', this.locals.name as string);
+    url.searchParams.set('work_package[initial][start_date]', this.nullAsEmptyStringFormatter(resource.startDate));
+    url.searchParams.set('work_package[initial][due_date]', this.nullAsEmptyStringFormatter(resource.dueDate));
+    url.searchParams.set('work_package[initial][duration]', this.nullAsEmptyStringFormatter(resource.duration));
+    url.searchParams.set('work_package[initial][ignore_non_working_days]', this.nullAsEmptyStringFormatter(resource.includeNonWorkingDays));
+
+    url.searchParams.set('work_package[start_date]', this.nullAsEmptyStringFormatter(resource.startDate));
+    url.searchParams.set('work_package[due_date]', this.nullAsEmptyStringFormatter(resource.dueDate));
+    url.searchParams.set('work_package[duration]', this.nullAsEmptyStringFormatter(resource.duration));
+    url.searchParams.set('work_package[ignore_non_working_days]', this.nullAsEmptyStringFormatter(resource.includeNonWorkingDays));
+    if (resource.id === 'new' && resource.startDate) {
       url.searchParams.set('work_package[start_date_touched]', 'true');
     }
 
     this.turboFrameSrc = url.toString();
   }
 
-  private nullAsEmptyStringFormatter(value:null|undefined|string):string {
+  private nullAsEmptyStringFormatter(value:null|undefined|string|boolean):string {
     if (value === undefined || value === null) {
       return '';
     }
-    return value;
+    return String(value);
   }
 }
diff --git a/frontend/src/app/shared/components/editable-toolbar-title/editable-toolbar-title.component.ts b/frontend/src/app/shared/components/editable-toolbar-title/editable-toolbar-title.component.ts
index d3730c056d31..2637ed9558d1 100644
--- a/frontend/src/app/shared/components/editable-toolbar-title/editable-toolbar-title.component.ts
+++ b/frontend/src/app/shared/components/editable-toolbar-title/editable-toolbar-title.component.ts
@@ -116,7 +116,7 @@ export class EditableToolbarTitleComponent implements OnInit, OnChanges {
 
   ngOnChanges(changes:SimpleChanges):void {
     if (changes.inputTitle) {
-      this.selectedTitle = changes.inputTitle.currentValue;
+      this.selectedTitle = changes.inputTitle.currentValue as string;
     }
 
     if (changes.initialFocus && changes.initialFocus.firstChange && this.inputField!) {
diff --git a/frontend/src/app/shared/components/grids/grid/area.service.ts b/frontend/src/app/shared/components/grids/grid/area.service.ts
index df824687f6f8..a7b1ea8892f9 100644
--- a/frontend/src/app/shared/components/grids/grid/area.service.ts
+++ b/frontend/src/app/shared/components/grids/grid/area.service.ts
@@ -53,6 +53,8 @@ interface GridPatchPayload {
   [key:string]:unknown;
 }
 
+type ScrollIntoViewIfNeededElement = HTMLElement&{ scrollIntoViewIfNeeded?:() => void };
+
 @Injectable()
 export class GridAreaService {
   private apiV3Service = inject(ApiV3Service);
@@ -207,10 +209,10 @@ export class GridAreaService {
   // But as scrollIntoView will always readjust the viewport, the result would be an unbearable flicker
   // which causes e.g. dragging to be impossible.
   public scrollPlaceholderIntoView() {
-    const placeholder = document.querySelector<HTMLElement>('.grid--area.-placeholder');
+    const placeholder = document.querySelector<ScrollIntoViewIfNeededElement>('.grid--area.-placeholder')!;
 
-    if ((placeholder as any).scrollIntoViewIfNeeded) {
-      setTimeout(() => (placeholder as any).scrollIntoViewIfNeeded());
+    if (placeholder.scrollIntoViewIfNeeded) {
+      setTimeout(() => placeholder.scrollIntoViewIfNeeded!());
     }
   }
 
diff --git a/frontend/src/app/shared/components/grids/grid/drag-and-drop.service.ts b/frontend/src/app/shared/components/grids/grid/drag-and-drop.service.ts
index 39c6f0cf4279..aa27a9c1301c 100644
--- a/frontend/src/app/shared/components/grids/grid/drag-and-drop.service.ts
+++ b/frontend/src/app/shared/components/grids/grid/drag-and-drop.service.ts
@@ -116,7 +116,7 @@ export class GridDragAndDropService implements OnDestroy {
   public start(area:GridWidgetArea) {
     this.placeholderArea = new GridWidgetArea(area.widget);
     // TODO find an angular way to do this that ideally does not require passing the element from the grid component
-    this.draggedHeight = (document as any).getElementById(area.guid).offsetHeight - 2; // border width * 2
+    this.draggedHeight = document.getElementById(area.guid)!.offsetHeight - 2; // border width * 2
     this.draggedArea = area;
   }
 
diff --git a/frontend/src/app/shared/components/grids/grid/grid.component.ts b/frontend/src/app/shared/components/grids/grid/grid.component.ts
index 4be2ce3f6508..cd4b3a206617 100644
--- a/frontend/src/app/shared/components/grids/grid/grid.component.ts
+++ b/frontend/src/app/shared/components/grids/grid/grid.component.ts
@@ -26,7 +26,7 @@
 // See COPYRIGHT and LICENSE files for more details.
 //++
 
-import { ChangeDetectionStrategy, ChangeDetectorRef, Component, ComponentRef, HostListener, Input, OnDestroy, OnInit, inject } from '@angular/core';
+import { ChangeDetectionStrategy, ChangeDetectorRef, Component, ComponentRef, HostListener, Input, OnDestroy, OnInit, Type, inject } from '@angular/core';
 import { GridResource } from 'core-app/features/hal/resources/grid-resource';
 import { DomSanitizer } from '@angular/platform-browser';
 import { GridWidgetsService } from 'core-app/shared/components/grids/widgets/widgets.service';
@@ -46,7 +46,7 @@ import { WidgetChangeset } from 'core-app/shared/components/grids/widgets/widget
 export interface WidgetRegistration {
   identifier:string;
   title:string;
-  component:new (...args:any[]) => AbstractWidgetComponent;
+  component:Type<AbstractWidgetComponent>;
   properties?:Record<string, unknown>;
 }
 
@@ -80,7 +80,7 @@ export class GridComponent implements OnDestroy, OnInit {
   readonly browserDetector = inject(BrowserDetector);
   readonly cdRef = inject(ChangeDetectorRef);
 
-  public uiWidgets:ComponentRef<any>[] = [];
+  public uiWidgets:ComponentRef<unknown>[] = [];
 
   public GRID_AREA_HEIGHT = 'auto';
 
diff --git a/frontend/src/app/shared/components/grids/widgets/custom-text/custom-text.component.ts b/frontend/src/app/shared/components/grids/widgets/custom-text/custom-text.component.ts
index fd2453663860..8cd01711af3f 100644
--- a/frontend/src/app/shared/components/grids/widgets/custom-text/custom-text.component.ts
+++ b/frontend/src/app/shared/components/grids/widgets/custom-text/custom-text.component.ts
@@ -35,6 +35,7 @@ import { HalResource } from 'core-app/features/hal/resources/hal-resource';
 import { filter } from 'rxjs/operators';
 import { GridAreaService } from 'core-app/shared/components/grids/grid/area.service';
 import { DomSanitizer, SafeHtml } from '@angular/platform-browser';
+import { GridWidgetResource } from 'core-app/features/hal/resources/grid-widget-resource';
 
 @Component({
   templateUrl: './custom-text.component.html',
@@ -83,7 +84,7 @@ export class WidgetCustomTextComponent extends AbstractWidgetComponent implement
   }
 
   ngOnChanges(changes:SimpleChanges):void {
-    if (changes.resource.currentValue.options.text.raw !== this.currentRawText) {
+    if (((changes.resource.currentValue as GridWidgetResource).options.text as HalResource).raw !== this.currentRawText) {
       this.setupVariables();
 
       this.cdr.detectChanges();
diff --git a/frontend/src/app/shared/components/grids/widgets/wp-graph/wp-graph.component.html b/frontend/src/app/shared/components/grids/widgets/wp-graph/wp-graph.component.html
index 2d2917cff4a8..07d812ba4a0a 100644
--- a/frontend/src/app/shared/components/grids/widgets/wp-graph/wp-graph.component.html
+++ b/frontend/src/app/shared/components/grids/widgets/wp-graph/wp-graph.component.html
@@ -5,7 +5,7 @@
   <widget-wp-graph-menu
       slot="menu"
       [resource]="resource"
-      (onConfigured)="updateGraph($event)" />
+      (onConfigured)="updateGraph()" />
 </widget-header>
 
 <op-wp-embedded-graph class='op-widget-box--body -no-overflow'
diff --git a/frontend/src/app/shared/components/grids/widgets/wp-graph/wp-graph.component.ts b/frontend/src/app/shared/components/grids/widgets/wp-graph/wp-graph.component.ts
index fccd1faaba08..0c00aefea045 100644
--- a/frontend/src/app/shared/components/grids/widgets/wp-graph/wp-graph.component.ts
+++ b/frontend/src/app/shared/components/grids/widgets/wp-graph/wp-graph.component.ts
@@ -57,7 +57,7 @@ export class WidgetWpGraphComponent extends AbstractWidgetComponent implements O
     this.resource.options.chartType = type;
   }
 
-  public updateGraph(config:any) {
+  public updateGraph():void {
     this.graphConfiguration.persistAndReload()
       .then(() => {
         this.repaint();
diff --git a/frontend/src/app/shared/components/modal/modal.types.ts b/frontend/src/app/shared/components/modal/modal.types.ts
index 832bfa5414e6..992502a64029 100644
--- a/frontend/src/app/shared/components/modal/modal.types.ts
+++ b/frontend/src/app/shared/components/modal/modal.types.ts
@@ -30,5 +30,5 @@ import { OpModalService } from './modal.service';
 
 export interface OpModalLocalsMap {
   service:OpModalService;
-  [key:string]:any;
+  [key:string]:unknown;
 }
diff --git a/frontend/src/app/shared/components/modals/editor/macro-child-pages-modal/child-pages-macro.modal.ts b/frontend/src/app/shared/components/modals/editor/macro-child-pages-modal/child-pages-macro.modal.ts
index d8990ed6458c..5aa4c99f2aa3 100644
--- a/frontend/src/app/shared/components/modals/editor/macro-child-pages-modal/child-pages-macro.modal.ts
+++ b/frontend/src/app/shared/components/modals/editor/macro-child-pages-modal/child-pages-macro.modal.ts
@@ -55,7 +55,7 @@ export class ChildPagesMacroModalComponent extends OpModalComponent implements A
 
   @ViewChild('selectedPageInput', { static: true }) selectedPageInput:ElementRef<HTMLInputElement>;
 
-  public text:any = {
+  public text = {
     title: this.I18n.t('js.editor.macro.child_pages.button'),
     hint: this.I18n.t('js.editor.macro.child_pages.hint'),
     page: this.I18n.t('js.editor.macro.child_pages.page'),
@@ -68,8 +68,8 @@ export class ChildPagesMacroModalComponent extends OpModalComponent implements A
   constructor() {
     super();
 
-    this.selectedPage = this.page = this.locals.page;
-    this.selectedIncludeParent = this.includeParent = this.locals.includeParent;
+    this.selectedPage = this.page = this.locals.page as string;
+    this.selectedIncludeParent = this.includeParent = this.locals.includeParent as boolean;
 
     // We could provide an autocompleter here to get correct page names
   }
diff --git a/frontend/src/app/shared/components/modals/editor/macro-code-block-modal/code-block-macro.modal.ts b/frontend/src/app/shared/components/modals/editor/macro-code-block-modal/code-block-macro.modal.ts
index 000562428ecb..1dda91bc2044 100644
--- a/frontend/src/app/shared/components/modals/editor/macro-code-block-modal/code-block-macro.modal.ts
+++ b/frontend/src/app/shared/components/modals/editor/macro-code-block-modal/code-block-macro.modal.ts
@@ -68,7 +68,7 @@ export class CodeBlockMacroModalComponent extends OpModalComponent implements Af
   readonly I18n = inject(I18nService);
   readonly codeMirrorLoader = inject(CodeMirrorLoaderService);
 
-  public text:any = {
+  public text = {
     title: this.I18n.t('js.editor.macro.code_block.title'),
     language: this.I18n.t('js.editor.macro.code_block.language'),
     language_hint: this.I18n.t('js.editor.macro.code_block.language_hint'),
diff --git a/frontend/src/app/shared/components/modals/editor/macro-wiki-include-page-modal/wiki-include-page-macro.modal.ts b/frontend/src/app/shared/components/modals/editor/macro-wiki-include-page-modal/wiki-include-page-macro.modal.ts
index ed02883395af..13ed41c4e21c 100644
--- a/frontend/src/app/shared/components/modals/editor/macro-wiki-include-page-modal/wiki-include-page-macro.modal.ts
+++ b/frontend/src/app/shared/components/modals/editor/macro-wiki-include-page-modal/wiki-include-page-macro.modal.ts
@@ -51,7 +51,7 @@ export class WikiIncludePageMacroModalComponent extends OpModalComponent impleme
 
   @ViewChild('selectedPageInput', { static: true }) selectedPageInput:ElementRef<HTMLInputElement>;
 
-  public text:any = {
+  public text = {
     title: this.I18n.t('js.editor.macro.wiki_page_include.button'),
     hint: this.I18n.t('js.editor.macro.wiki_page_include.hint'),
     page: this.I18n.t('js.editor.macro.wiki_page_include.page'),
@@ -63,7 +63,7 @@ export class WikiIncludePageMacroModalComponent extends OpModalComponent impleme
   constructor() {
     super();
 
-    this.selectedPage = this.page = this.locals.page;
+    this.selectedPage = this.page = this.locals.page as string;
 
     // We could provide an autocompleter here to get correct page names
   }
diff --git a/frontend/src/app/shared/components/modals/editor/macro-wp-button-modal/wp-button-macro.modal.ts b/frontend/src/app/shared/components/modals/editor/macro-wp-button-modal/wp-button-macro.modal.ts
index 03a3e812ae19..ff6ad113bfbb 100644
--- a/frontend/src/app/shared/components/modals/editor/macro-wp-button-modal/wp-button-macro.modal.ts
+++ b/frontend/src/app/shared/components/modals/editor/macro-wp-button-modal/wp-button-macro.modal.ts
@@ -60,7 +60,7 @@ export class WpButtonMacroModalComponent extends OpModalComponent implements Aft
 
   @ViewChild('typeSelect', { static: true }) typeSelect:ElementRef<HTMLSelectElement>;
 
-  public text:any = {
+  public text = {
     title: this.I18n.t('js.editor.macro.work_package_button.button'),
     none: this.I18n.t('js.label_none'),
     selected_type: this.I18n.t('js.editor.macro.work_package_button.type'),
@@ -74,8 +74,8 @@ export class WpButtonMacroModalComponent extends OpModalComponent implements Aft
   constructor() {
     super();
 
-    this.selectedType = this.type = this.locals.type;
-    this.classes = this.locals.classes;
+    this.selectedType = this.type = this.locals.type as string;
+    this.classes = this.locals.classes as string;
     this.buttonStyle = this.classes === 'button';
 
     this
diff --git a/frontend/src/app/shared/components/option-list/option-list.component.ts b/frontend/src/app/shared/components/option-list/option-list.component.ts
index d43ad4aa2413..d86ec57dba2e 100644
--- a/frontend/src/app/shared/components/option-list/option-list.component.ts
+++ b/frontend/src/app/shared/components/option-list/option-list.component.ts
@@ -92,11 +92,11 @@ export class OpOptionListComponent<T> implements ControlValueAccessor {
     this.cdRef.markForCheck();
   }
 
-  registerOnChange(fn:any) {
+  registerOnChange(fn:(_:IOpOptionListValue<T>) => void) {
     this.onChange = fn;
   }
 
-  registerOnTouched(fn:any) {
+  registerOnTouched(fn:(_:IOpOptionListValue<T>) => void) {
     this.onTouched = fn;
   }
 }
diff --git a/frontend/src/app/shared/components/principal/principal-types.ts b/frontend/src/app/shared/components/principal/principal-types.ts
index 34c100b3d0d5..1c6c2603edac 100644
--- a/frontend/src/app/shared/components/principal/principal-types.ts
+++ b/frontend/src/app/shared/components/principal/principal-types.ts
@@ -38,5 +38,5 @@ export type PrincipalLike =
 
 export interface PrincipalData {
   principal:PrincipalLike|null;
-  customFields:Record<string, any>,
+  customFields:Record<string, unknown>,
 }
diff --git a/frontend/src/app/shared/components/remote-field-updater/remote-field-updater.component.ts b/frontend/src/app/shared/components/remote-field-updater/remote-field-updater.component.ts
index 04da91526c67..44ec22156843 100644
--- a/frontend/src/app/shared/components/remote-field-updater/remote-field-updater.component.ts
+++ b/frontend/src/app/shared/components/remote-field-updater/remote-field-updater.component.ts
@@ -133,7 +133,7 @@ export class RemoteFieldUpdaterComponent implements OnInit, OnDestroy {
     this
       .request(params)
       .subscribe((response:object) => {
-        Object.entries(response).forEach(([selector, val]) => {
+        Object.entries(response as Record<string, string>).forEach(([selector, val]) => {
           const element = document.getElementById(selector) as HTMLElement|HTMLInputElement;
 
           if (element instanceof HTMLInputElement) {
diff --git a/frontend/src/app/shared/components/time_entries/edit/trigger-actions-entry.component.ts b/frontend/src/app/shared/components/time_entries/edit/trigger-actions-entry.component.ts
index 9e287e91af00..b119fe942d28 100644
--- a/frontend/src/app/shared/components/time_entries/edit/trigger-actions-entry.component.ts
+++ b/frontend/src/app/shared/components/time_entries/edit/trigger-actions-entry.component.ts
@@ -37,6 +37,7 @@ import { TimeEntryResource } from 'core-app/features/hal/resources/time-entry-re
 import { Observable, switchMap } from 'rxjs';
 import { PathHelperService } from 'core-app/core/path-helper/path-helper.service';
 import { TurboRequestsService } from 'core-app/core/turbo/turbo-requests.service';
+import { HttpErrorResponse } from '@angular/common/http';
 
 @Component({
   selector: 'opce-time-entry-trigger-actions',
@@ -114,7 +115,7 @@ export class TriggerActionsEntryComponent {
       )
       .subscribe(
         () => window.location.reload(),
-        (error) => this.toastService.addError(error || this.text.error),
+        (error:HttpErrorResponse) => this.toastService.addError(error || this.text.error),
       );
   }
 
diff --git a/frontend/src/app/shared/components/work-package-graphs/configuration-modal/wp-graph-configuration.modal.ts b/frontend/src/app/shared/components/work-package-graphs/configuration-modal/wp-graph-configuration.modal.ts
index cee7178c858a..4eea1c8e3fbc 100644
--- a/frontend/src/app/shared/components/work-package-graphs/configuration-modal/wp-graph-configuration.modal.ts
+++ b/frontend/src/app/shared/components/work-package-graphs/configuration-modal/wp-graph-configuration.modal.ts
@@ -42,7 +42,7 @@ import { WpGraphConfigurationService } from 'core-app/shared/components/work-pac
 import { WpGraphConfiguration } from 'core-app/shared/components/work-package-graphs/configuration/wp-graph-configuration';
 import { WorkPackageNotificationService } from 'core-app/features/work-packages/services/notifications/work-package-notification.service';
 
-export const WpTableConfigurationModalPrependToken = new InjectionToken<ComponentType<any>>('WpTableConfigurationModalPrependComponent');
+export const WpTableConfigurationModalPrependToken = new InjectionToken<ComponentType<unknown>>('WpTableConfigurationModalPrependComponent');
 
 @Component({
   templateUrl: '../../../../features/work-packages/components/wp-table/configuration-modal/wp-table-configuration.modal.html',
diff --git a/frontend/src/app/shared/components/work-package-graphs/configuration/wp-graph-configuration.service.ts b/frontend/src/app/shared/components/work-package-graphs/configuration/wp-graph-configuration.service.ts
index 8535b58f4d50..8f7842b1a39e 100644
--- a/frontend/src/app/shared/components/work-package-graphs/configuration/wp-graph-configuration.service.ts
+++ b/frontend/src/app/shared/components/work-package-graphs/configuration/wp-graph-configuration.service.ts
@@ -128,7 +128,6 @@ export class WpGraphConfigurationService {
       .apiv3Service
       .queries
       .find(
-        // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
         { pageSize: 0, ...params.props },
         params.id,
         this.projectIdentifier(),
diff --git a/frontend/src/app/shared/components/work-package-graphs/configuration/wp-graph-configuration.ts b/frontend/src/app/shared/components/work-package-graphs/configuration/wp-graph-configuration.ts
index 3a8679a93cd2..5443c2e71137 100644
--- a/frontend/src/app/shared/components/work-package-graphs/configuration/wp-graph-configuration.ts
+++ b/frontend/src/app/shared/components/work-package-graphs/configuration/wp-graph-configuration.ts
@@ -32,18 +32,11 @@ import { I18nService } from 'core-app/core/i18n/i18n.service';
 
 export interface WpGraphQueryParams {
   id?:string;
-  props?:any;
+  props?:object;
   name?:string;
 }
 
-export interface WpGraphConfiguration {
-  queries:QueryResource[];
-  queryParams:WpGraphQueryParams[];
-  chartType:string;
-  chartOptions:ChartOptions;
-}
-
-export class WpGraphConfiguration implements WpGraphConfiguration {
+export class WpGraphConfiguration {
   public queries:QueryResource[] = [];
 
   constructor(
diff --git a/frontend/src/app/shared/components/work-package-graphs/embedded/wp-embedded-graph.component.ts b/frontend/src/app/shared/components/work-package-graphs/embedded/wp-embedded-graph.component.ts
index c219d3fdff97..eb340633d9a7 100644
--- a/frontend/src/app/shared/components/work-package-graphs/embedded/wp-embedded-graph.component.ts
+++ b/frontend/src/app/shared/components/work-package-graphs/embedded/wp-embedded-graph.component.ts
@@ -38,7 +38,7 @@ import { chartTypeLocaleKey } from './../chart-type';
 
 export interface WorkPackageEmbeddedGraphDataset {
   label:string;
-  queryProps:any;
+  queryProps:unknown;
   queryId?:number|string;
   groups?:GroupObject[];
 }
@@ -106,24 +106,24 @@ export class WorkPackageEmbeddedGraphComponent implements OnChanges {
   }
 
   private updateChartData() {
-    let uniqLabels = Array.from(new Set(this.datasets.reduce((array, dataset) => {
-      const groups = (dataset.groups || []).map((group) => group.value) as any;
+    const uniqLabels = Array.from(new Set(this.datasets.reduce<(string|null)[]>((array, dataset) => {
+      const groups = (dataset.groups ?? []).map((group) => group.value as string|null);
       return array.concat(groups);
-    }, []))) as string[];
+    }, [])));
 
     const labelCountMaps = this.datasets.map((dataset) => {
-      const countMap = (dataset.groups || []).reduce<any>((hash, group) => ({
+      const countMap = (dataset.groups ?? []).reduce<Record<string, number>>((hash, group) => ({
         ...hash,
         [group.value]: group.count,
       }), {});
 
       return {
         label: dataset.label,
-        data: uniqLabels.map((label) => countMap[label] || 0),
+        data: uniqLabels.map((label) => countMap[String(label)] || 0),
       };
     });
 
-    uniqLabels = uniqLabels.map((label) => {
+    const displayLabels = uniqLabels.map((label) => {
       if (label === null) {
         return this.i18n.t('js.placeholders.default');
       }
@@ -134,7 +134,7 @@ export class WorkPackageEmbeddedGraphComponent implements OnChanges {
 
     // keep the array in order to update the labels
     this.chartLabels.length = 0;
-    this.chartLabels.push(...uniqLabels);
+    this.chartLabels.push(...displayLabels);
     this.chartData.length = 0;
     this.chartData.push(...labelCountMaps);
   }
diff --git a/frontend/src/app/spot/components/drop-modal/drop-modal-teleportation.service.ts b/frontend/src/app/spot/components/drop-modal/drop-modal-teleportation.service.ts
index ac395fcbe7ec..bb9c26b32cb0 100644
--- a/frontend/src/app/spot/components/drop-modal/drop-modal-teleportation.service.ts
+++ b/frontend/src/app/spot/components/drop-modal/drop-modal-teleportation.service.ts
@@ -36,7 +36,7 @@ import {
 } from 'rxjs';
 import { distinctUntilChanged, filter, take } from 'rxjs/operators';
 
-export type TeleportInstance = TemplateRef<any>;
+export type TeleportInstance = TemplateRef<unknown>;
 
 @Injectable({ providedIn: 'root' })
 export class SpotDropModalTeleportationService {