diff --git a/src/app/components/add-task/add-task.component.ts b/src/app/components/add-task/add-task.component.ts
index ddc3af7..615dbc9 100644
--- a/src/app/components/add-task/add-task.component.ts
+++ b/src/app/components/add-task/add-task.component.ts
@@ -59,6 +59,7 @@ export class AddTaskComponent implements OnInit {
     subtasksDone: [],
     assigned: [],
     assignees: [],
+    userData: [],
     creator: this.firebaseService.getCurrentUserId(),
     date: this.currentDate,
   };
diff --git a/src/app/components/board/board.component.ts b/src/app/components/board/board.component.ts
index cbbbf5e..cc2bd21 100644
--- a/src/app/components/board/board.component.ts
+++ b/src/app/components/board/board.component.ts
@@ -11,7 +11,7 @@ import { TranslateModule } from '@ngx-translate/core';
 import { TaskHighlightedComponent } from './task/task-highlighted/task-highlighted.component';
 import { ApiService } from '../../services/api.service';
 import { Task } from '../../interfaces/task.interface';
-import { forkJoin } from 'rxjs';
+import { TaskService } from '../../services/task.service';
 
 @Component({
   selector: 'app-board',
@@ -37,6 +37,7 @@ export class BoardComponent {
     public dragDropService: DragDropService,
     public overlayService: OverlayService,
     private sharedService: SharedService,
+    private taskService: TaskService,
     private apiService: ApiService,
     private router: Router
   ) {}
@@ -62,22 +63,15 @@ export class BoardComponent {
    * Retrieves all tasks from the API and initializes the `allTasks` and `filteredTasks` properties.
    */
   loadTasks(): void {
-    const statuses = [
-      this.TODO,
-      this.IN_PROGRESS,
-      this.AWAIT_FEEDBACK,
-      this.DONE,
-    ];
-    const requests = statuses.map((status) =>
-      this.apiService.getTasksByStatus(status)
-    );
+    this.taskService.loadAllTasks().subscribe({
+      next: (result) => {
+        this.allTasks = result.allTasks;
+        this.filteredTasks = result.filteredTasks;
+      },
 
-    forkJoin(requests).subscribe((results) => {
-      this.allTasks = results.flat();
-      this.filteredTasks = statuses.reduce((acc, status, index) => {
-        acc[status] = results[index];
-        return acc;
-      }, {} as { [key: string]: Task[] });
+      error: (err) => {
+        console.error('Error loading the tasks:', err);
+      },
     });
   }
 
diff --git a/src/app/components/board/task/task.component.html b/src/app/components/board/task/task.component.html
index 1847982..c27b810 100644
--- a/src/app/components/board/task/task.component.html
+++ b/src/app/components/board/task/task.component.html
@@ -27,7 +27,7 @@
       <div class="description">
         {{ task.description }}
       </div>
-      @if(task.subtasksTitle.length > 0) {
+      @if(task.subtasks.length > 0) {
       <div class="subtask">
         <div class="subtask-line">
           <span
@@ -36,28 +36,31 @@
           ></span>
         </div>
         <div class="subtask-text">
-          {{ completedSubtasks() }} / {{ task.subtasksTitle.length }} Subtasks
+          {{ completedSubtasks() }} / {{ task.subtasks.length }} Subtasks
         </div>
       </div>
       }
       <div class="footer">
         <div class="footer-badge">
+          @for (user of task.userData; track user) { @if (task.creator ===
+          user.id) {
           <span
             class="footer-badged"
             (mousemove)="openDialog(task.creator, $event)"
             (mouseleave)="closeDialog()"
-            [style.background-color]="userBadgedColor(task.creator)"
-            >{{ userBadged(task.creator) }}</span
+            [style.background-color]="user.color"
+            >{{ user.initials }}</span
           >
-          @for (assigned of task.assigned; track assigned) {
+          } @for (assigned of task.assignees; track assigned.id) { @if
+          (assigned.user === user.id) {
           <span
             class="footer-badged"
-            (mousemove)="openDialog(assigned, $event)"
+            (mousemove)="openDialog(user.id, $event)"
             (mouseleave)="closeDialog()"
-            [style.background-color]="userBadgedColor(assigned)"
-            >{{ userBadged(assigned) }}</span
+            [style.background-color]="user.color"
+            >{{ user.initials }}</span
           >
-          }
+          } } }
         </div>
         <div class="footer-priority prio-{{ task.priority }}"></div>
       </div>
@@ -70,14 +73,15 @@
   ></app-task-menu>
   } @if (AssignedDialogId != '') {
   <div class="dialog" [style.left.px]="dialogX" [style.top.px]="dialogY">
+    @for (user of task.userData; track user) { @if (user.id ===
+    AssignedDialogId) {
     <p>
-      {{ firebaseService.getUserDetails(AssignedDialogId, "firstName") }}
-      @if (AssignedDialogId === firebaseService.getCurrentUserId()) {
-      <span>(du)</span> }
+      {{ user.firstName }}
     </p>
     <p>
-      {{ firebaseService.getUserDetails(AssignedDialogId, "lastName") }}
+      {{ user.lastName }}
     </p>
+    }}
   </div>
   } }
 </section>
diff --git a/src/app/components/board/task/task.component.ts b/src/app/components/board/task/task.component.ts
index 1198625..95ba6c5 100644
--- a/src/app/components/board/task/task.component.ts
+++ b/src/app/components/board/task/task.component.ts
@@ -22,6 +22,9 @@ export class TaskComponent {
   dialogX: number = 0;
   dialogY: number = 0;
 
+  creator: any = '';
+  assignees: any[] = [];
+
   categoryColors = new Map<string, string>([
     ['User Story', '#0038ff'],
     ['Technical Task', '#20d7c2'],
@@ -129,8 +132,7 @@ export class TaskComponent {
    * @returns the number of completed subtasks
    */
   completedSubtasks(): number {
-    return this.task.subtasksDone.filter((subtask: boolean) => subtask === true)
-      .length;
+    return this.task.subtasks.filter((subtask) => subtask.done).length;
   }
 
   /**
@@ -138,12 +140,11 @@ export class TaskComponent {
    * @returns the percentage of completed subtasks as a number
    */
   completedSubtasksPercent(): number {
-    const subtasks = this.task.subtasksDone;
-    const completedSubtasksCount = subtasks.filter(
-      (subtask: boolean) => subtask === true
+    const completedSubtasksCount = this.task.subtasks.filter(
+      (subtask) => subtask.done
     ).length;
 
-    return (completedSubtasksCount / subtasks.length) * 100;
+    return (completedSubtasksCount / this.task.subtasks.length) * 100;
   }
 
   // Assigned
diff --git a/src/app/interfaces/task.interface.ts b/src/app/interfaces/task.interface.ts
index e14fd28..0776d21 100644
--- a/src/app/interfaces/task.interface.ts
+++ b/src/app/interfaces/task.interface.ts
@@ -1,3 +1,5 @@
+import { UserSummary } from './user.interface';
+
 export interface Task {
   id?: string;
   title: string;
@@ -9,7 +11,8 @@ export interface Task {
   subtasksTitle: string[];
   subtasksDone: boolean[];
   assigned: string[];
-  assignees: string[];
+  assignees: Assignee[];
+  userData: UserSummary[];
   creator: string;
   date: string;
 }
@@ -19,3 +22,9 @@ export interface Subtask {
   title: string;
   done: boolean;
 }
+
+export interface Assignee {
+  id: string;
+  user: string;
+  task: string;
+}
diff --git a/src/app/interfaces/user.interface.ts b/src/app/interfaces/user.interface.ts
index c631ff3..8d6e809 100644
--- a/src/app/interfaces/user.interface.ts
+++ b/src/app/interfaces/user.interface.ts
@@ -10,3 +10,11 @@ export interface User {
   status: boolean;
   lastLogin: number;
 }
+
+export interface UserSummary {
+  id?: string;
+  firstName: string;
+  lastName: string;
+  initials: string;
+  color: string;
+}
diff --git a/src/app/services/api.service.ts b/src/app/services/api.service.ts
index 28dd9db..2d96b12 100644
--- a/src/app/services/api.service.ts
+++ b/src/app/services/api.service.ts
@@ -1,8 +1,9 @@
-import { Injectable } from '@angular/core';
+import { Injectable, signal } from '@angular/core';
 import { HttpClient } from '@angular/common/http';
 import { Observable } from 'rxjs';
 import { apiConfig } from '../environments/config';
 import { Task } from '../interfaces/task.interface';
+import { User } from '../interfaces/user.interface';
 
 @Injectable({
   providedIn: 'root',
@@ -14,6 +15,10 @@ export class ApiService {
 
   // ------------- TASKS ------------- //
 
+  getTaskById(taskId: string): Observable<Task> {
+    return this.http.get<Task>(`${this.apiUrl}/api/tasks/${taskId}/`);
+  }
+
   getTasksByStatus(status: string): Observable<Task[]> {
     return this.http.get<Task[]>(`${this.apiUrl}/api/tasks/`, {
       params: { status },
@@ -26,4 +31,12 @@ export class ApiService {
       { status: status }
     );
   }
+
+  // ------------- USERS ------------- //
+
+  getUsersByIds(userIds: string[]): Observable<User[]> {
+    return this.http.get<User[]>(`${this.apiUrl}/api/users/`, {
+      params: { ids: userIds.join(',') },
+    });
+  }
 }
diff --git a/src/app/services/task.service.ts b/src/app/services/task.service.ts
new file mode 100644
index 0000000..2107d59
--- /dev/null
+++ b/src/app/services/task.service.ts
@@ -0,0 +1,130 @@
+import { Injectable } from '@angular/core';
+import { Observable, forkJoin, of } from 'rxjs';
+import { ApiService } from './api.service';
+import { Task } from '../interfaces/task.interface';
+import { catchError, map, switchMap } from 'rxjs/operators';
+import { UserSummary } from '../interfaces/user.interface';
+
+@Injectable({ providedIn: 'root' })
+export class TaskService {
+  private readonly statuses = ['todo', 'inprogress', 'awaitfeedback', 'done'];
+
+  constructor(private apiService: ApiService) {}
+
+  loadAllTasks(): Observable<{
+    allTasks: Task[];
+    filteredTasks: Record<string, Task[]>;
+  }> {
+    return forkJoin(
+      this.statuses.map((status) => this.fetchTasksByStatus(status))
+    ).pipe(
+      switchMap((results) => {
+        const allTasks = results.flat();
+        const filteredTasks = this.statuses.reduce((acc, status, index) => {
+          acc[status] = results[index] || [];
+          return acc;
+        }, {} as Record<string, Task[]>);
+
+        return this.loadUsersForTasks(allTasks).pipe(
+          map((tasksWithUsers) => {
+            const updatedFilteredTasks = this.statuses.reduce((acc, status) => {
+              acc[status] = tasksWithUsers.filter(
+                (task) => task.status === status
+              );
+              return acc;
+            }, {} as Record<string, Task[]>);
+
+            return {
+              allTasks: tasksWithUsers,
+              filteredTasks: updatedFilteredTasks,
+            };
+          })
+        );
+      })
+    );
+  }
+
+  private fetchTasksByStatus(status: string): Observable<Task[]> {
+    return this.apiService.getTasksByStatus(status).pipe(
+      catchError((error) => {
+        console.error(
+          `Fehler beim Abrufen von Tasks für Status ${status}:`,
+          error
+        );
+        return of([]);
+      })
+    );
+  }
+
+  private loadUsersForTasks(tasks: Task[]): Observable<Task[]> {
+    const userIds = new Set(
+      tasks.flatMap((task) => [
+        task.creator,
+        ...task.assignees.map((a) => a.user),
+      ])
+    );
+
+    return this.apiService.getUsersByIds([...userIds]).pipe(
+      catchError((error) => {
+        console.error('Fehler beim Abrufen der Benutzer:', error);
+        return of([]);
+      }),
+      map((users) => {
+        const userMap = this.createUserMap(users);
+        return tasks.map((task) => ({
+          ...task,
+          userData: [
+            ...task.assignees.map((a) => userMap[a.user] || null),
+            userMap[task.creator] || null,
+          ].filter(Boolean),
+        }));
+      })
+    );
+  }
+
+  loadSingleTask(taskId: string): Observable<Task | null> {
+    return this.apiService.getTaskById(taskId).pipe(
+      switchMap((task) => {
+        if (!task) return of(null);
+        const userIds = [task.creator, ...task.assignees.map((a) => a.user)];
+
+        return this.apiService.getUsersByIds(userIds).pipe(
+          map((users) => ({
+            ...task,
+            userData: this.mapTaskUsers(task, users),
+          })),
+          catchError((error) => {
+            console.error('Fehler beim Abrufen der Benutzerdaten:', error);
+            return of(task);
+          })
+        );
+      }),
+      catchError((error) => {
+        console.error('Fehler beim Laden des Tasks:', error);
+        return of(null);
+      })
+    );
+  }
+
+  private createUserMap(users: UserSummary[]): Record<string, UserSummary> {
+    return users.reduce((acc, user) => {
+      if (user?.id)
+        acc[user.id] = {
+          id: user.id,
+          firstName: user.firstName,
+          lastName: user.lastName,
+          initials: user.initials,
+          color: user.color,
+        };
+      return acc;
+    }, {} as Record<string, UserSummary>);
+  }
+
+  private mapTaskUsers(task: Task, users: UserSummary[]): UserSummary[] {
+    const userMap = this.createUserMap(users);
+    return [
+      ...task.assignees.map((a) => userMap[a.user] || null),
+      userMap[task.creator] || null,
+    ].filter(Boolean);
+  }
+}
diff --git a/src/app/shared/components/overlay/task-overlay/task-overlay.component.html b/src/app/shared/components/overlay/task-overlay/task-overlay.component.html
index bb0062e..424d9b4 100644
--- a/src/app/shared/components/overlay/task-overlay/task-overlay.component.html
+++ b/src/app/shared/components/overlay/task-overlay/task-overlay.component.html
@@ -3,16 +3,14 @@
   overlay: !overlayMobile,
   'overlay-mobile': overlayMobile,
 }"
-  *ngIf="overlayData !== '' && getTaskData(overlayData).length > 0"
+  *ngIf="overlayData !== '' && task != null"
 >
   <div class="header">
     <div
       class="category"
-      [style.background-color]="
-        categoryColors.get(getTaskData(overlayData)[0].category)
-      "
+      [style.background-color]="categoryColors.get(task.category)"
     >
-      {{ getTaskData(overlayData)[0].category }}
+      {{ task.category }}
     </div>
     @if (overlayMobile) {
     <app-btn-back></app-btn-back>
@@ -26,126 +24,104 @@
     'content-mobile': overlayMobile,
   }"
   >
-    <div class="headline">{{ getTaskData(overlayData)[0].title }}</div>
+    <div class="headline">{{ task.title }}</div>
     <div class="description">
-      {{ getTaskData(overlayData)[0].description }}
+      {{ task.description }}
     </div>
     <div class="date">
       <p>{{ "addTask.date" | translate }}:</p>
-      {{ timeConverter(getTaskData(overlayData)[0].date) }}
+      {{ timeConverter(task.date) }}
     </div>
     <div class="priority">
       <p>{{ "addTask.priority" | translate }}:</p>
-      {{ capitalizeFirstLetter(getTaskData(overlayData)[0].priority) }}
-      <div
-        class="priority-bg priority-{{ getTaskData(overlayData)[0].priority }}"
-      ></div>
+      {{ capitalizeFirstLetter(task.priority) }}
+      <div class="priority-bg priority-{{ task.priority }}"></div>
     </div>
+
     <div class="creator">
       <p>{{ "addTask.creator" | translate }}:</p>
+      @for (user of task.userData; track user) { @if (task.creator === user.id)
+      {
       <div class="users">
         <div
           class="circle"
           [ngStyle]="{
-            'background-color': firebaseService.getUserDetails(
-              getTaskData(overlayData)[0].creator,
-              'color'
-            )
+            'background-color': user.color
           }"
         >
           <div class="initials">
-            {{
-              firebaseService.getUserDetails(
-                getTaskData(overlayData)[0].creator,
-                "initials"
-              )
-            }}
+            {{ user.initials }}
           </div>
         </div>
         <div class="details">
           <div class="name">
             <p>
-              {{
-                firebaseService.getUserDetails(
-                  getTaskData(overlayData)[0].creator,
-                  "firstName"
-                )
-              }}
+              {{ user.firstName }}
             </p>
             <span>&nbsp;</span>
             <p class="last-name">
-              {{
-                firebaseService.getUserDetails(
-                  getTaskData(overlayData)[0].creator,
-                  "lastName"
-                )
-              }}
+              {{ user.lastName }}
             </p>
           </div>
         </div>
       </div>
+      } }
     </div>
-    @if (getTaskData(overlayData)[0].assigned.length > 0) {
+    @if (task.assignees.length > 0) {
     <div class="assigned">
       <p>{{ "addTask.assigned" | translate }}:</p>
-      @for (user of getTaskData(overlayData)[0].assigned; track user) {
+      @for (assigned of task.assignees; track assigned.id) { @for (user of
+      task.userData; track user) { @if (assigned.user === user.id) {
       <div class="users">
         <div
           class="circle"
           [ngStyle]="{
-            'background-color': firebaseService.getUserDetails(user, 'color')
+            'background-color': user.color
           }"
         >
           <div class="initials">
-            {{ firebaseService.getUserDetails(user, "initials") }}
+            {{ user.initials }}
           </div>
         </div>
         <div class="details">
           <div class="name">
             <p>
-              {{ firebaseService.getUserDetails(user, "firstName") }}
+              {{ user.firstName }}
             </p>
             <span>&nbsp;</span>
             <p class="last-name">
-              {{ firebaseService.getUserDetails(user, "lastName") }}
+              {{ user.lastName }}
             </p>
           </div>
         </div>
       </div>
-      }
+      } } }
     </div>
-    } @if (getTaskData(overlayData)[0].subtasksTitle.length > 0) {
+    } @if (task.subtasks.length > 0) {
     <div class="subtasks">
       <p>{{ "addTask.subtask" | translate }}:</p>
-      @for (subtask of getTaskData(overlayData)[0].subtasksTitle; track subtask;
-      let i = $index) {
+      @for (subtask of task.subtasks; track subtask; let i = $index) {
       <div
         class="single-subtask"
         (click)="
-          toggleSubtaskStatus(
-            overlayData,
-            i,
-            getTaskData(overlayData)[0].subtasksDone,
-            getSubTaskStatus(overlayData, i)
-          )
+          toggleSubtaskStatus(overlayData, i, task.subtasksDone, subtask.done)
         "
       >
         <img
           [src]="
-            getSubTaskStatus(overlayData, i)
+            subtask.done
               ? './../../../../../assets/img/board/check-btn-checked.svg'
               : './../../../../../assets/img/board/check-btn-unchecked.svg'
           "
           alt=""
         />
-        <p>{{ subtask }}</p>
+        <p>{{ subtask.title }}</p>
       </div>
       }
     </div>
     }
   </div>
-  @if(getTaskData(overlayData)[0].creator ===
-  firebaseService.getCurrentUserId()) {
+  @if(task.creator === firebaseService.getCurrentUserId()) {
   <div class="btns">
     <div class="btn btn-delete" (click)="deleteTask(overlayData)">
       <img src="./../../../../../assets/img/contact/delete.svg" alt="" />
diff --git a/src/app/shared/components/overlay/task-overlay/task-overlay.component.ts b/src/app/shared/components/overlay/task-overlay/task-overlay.component.ts
index 684aaea..0726f84 100644
--- a/src/app/shared/components/overlay/task-overlay/task-overlay.component.ts
+++ b/src/app/shared/components/overlay/task-overlay/task-overlay.component.ts
@@ -6,6 +6,8 @@ import { OverlayService } from '../../../../services/overlay.service';
 import { ActivatedRoute, Router } from '@angular/router';
 import { BtnBackComponent } from '../../buttons/btn-back/btn-back.component';
 import { TranslateModule } from '@ngx-translate/core';
+import { Task } from '../../../../interfaces/task.interface';
+import { TaskService } from '../../../../services/task.service';
 
 @Component({
   selector: 'app-task-overlay',
@@ -18,11 +20,13 @@ export class TaskOverlayComponent implements OnInit {
   @Input() overlayData: string = '';
   @Output() closeDialogEmitter = new EventEmitter<string>();
 
+  task: Task | null = null;
   overlayMobile: boolean = false;
 
   constructor(
     public firebaseService: FirebaseService,
     private overlayService: OverlayService,
+    private taskService: TaskService,
     private router: Router,
     private route: ActivatedRoute
   ) {}
@@ -40,16 +44,30 @@ export class TaskOverlayComponent implements OnInit {
    * Also sets `overlayMobile` to `true` if parameters are successfully retrieved.
    */
   ngOnInit() {
-    if (this.overlayData == '') {
-      if (this.route.params.subscribe()) {
-        this.route.params.subscribe((params) => {
-          this.overlayData = params['id'];
-          this.overlayMobile = true;
-        });
-      }
+    this.setOverlayDataFromRoute();
+    this.loadTask(this.overlayData);
+  }
+
+  setOverlayDataFromRoute() {
+    if (this.overlayData === '') {
+      this.route.params.subscribe((params) => {
+        this.overlayData = params['id'];
+        this.overlayMobile = true;
+      });
     }
   }
 
+  loadTask(taskId: string) {
+    this.taskService.loadSingleTask(taskId).subscribe({
+      next: (task) => {
+        this.task = task;
+      },
+      error: (err) => {
+        console.error('Error loading the task:', err);
+      },
+    });
+  }
+
   /**
    * Close the task overlay.
    *
@@ -89,40 +107,6 @@ export class TaskOverlayComponent implements OnInit {
     this.closeDialog();
   }
 
-  /**
-   * Gets the task data from the Firebase Realtime Database for the given task id.
-   *
-   * This function takes a task id and returns an array of tasks with the given id.
-   * The function uses the Firebase service to get all tasks from the Realtime Database
-   * and then filters the result to return only the task with the given id.
-   *
-   * @param taskId The id of the task to be retrieved.
-   * @returns {Task[]} An array of tasks with the given id.
-   */
-  getTaskData(taskId: string) {
-    return this.firebaseService
-      .getAllTasks()
-      .filter((task) => task.id === taskId);
-  }
-
-  /**
-   * Retrieves the status of a single subtask of a task.
-   *
-   * This function takes the task id and the index of the subtask
-   * and returns the status of the subtask at the given index.
-   *
-   * @param taskId The task id of the task containing the subtask.
-   * @param index The index of the subtask.
-   * @returns {boolean} The status of the subtask at the given index.
-   */
-  getSubTaskStatus(taskId: string, index: number) {
-    const subtask = this.firebaseService
-      .getAllTasks()
-      .filter((task) => task.id === taskId);
-
-    return subtask[0].subtasksDone[index];
-  }
-
   /**
    * Toggles the status of a single subtask of a task.
    *