diff --git a/backend/internal/api/handlers/core_handlers.go b/backend/internal/api/handlers/core_handlers.go
index 47b4527..94c3ffb 100644
--- a/backend/internal/api/handlers/core_handlers.go
+++ b/backend/internal/api/handlers/core_handlers.go
@@ -760,19 +760,14 @@ func (h *CoreHandlers) Me(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	var userID int
+	var userID string
 	switch v := userIDVal.(type) {
 	case int:
-		userID = v
+		userID = strconv.Itoa(v)
 	case string:
-		var err error
-		userID, err = strconv.Atoi(v)
-		if err != nil {
-			http.Error(w, "Invalid User ID in context", http.StatusInternalServerError)
-			return
-		}
+		userID = v
 	case float64:
-		userID = int(v)
+		userID = strconv.Itoa(int(v))
 	}
 
 	user, err := h.adminService.GetUser(ctx, userID)
diff --git a/backend/internal/dto/auth.go b/backend/internal/dto/auth.go
index 33cfad2..37f8f79 100755
--- a/backend/internal/dto/auth.go
+++ b/backend/internal/dto/auth.go
@@ -15,12 +15,12 @@ type LoginResponse struct {
 	Token           string        `json:"token"`
 	User            UserInfo      `json:"user"`
 	Companies       []CompanyInfo `json:"companies,omitempty"`
-	ActiveCompanyID *int          `json:"activeCompanyId,omitempty"`
+	ActiveCompanyID *string       `json:"activeCompanyId,omitempty"`
 }
 
 // UserInfo represents basic user information in responses
 type UserInfo struct {
-	ID         int    `json:"id"`
+	ID         string `json:"id"`
 	Identifier string `json:"identifier"`
 	Role       string `json:"role"`
 	FullName   string `json:"fullName"`
@@ -29,7 +29,7 @@ type UserInfo struct {
 
 // CompanyInfo represents basic company information
 type CompanyInfo struct {
-	ID   int    `json:"id"`
+	ID   string `json:"id"`
 	Name string `json:"name"`
 	Role string `json:"role"` // Role in this company (admin or recruiter)
 }
@@ -49,7 +49,7 @@ type RegisterRequest struct {
 
 // User represents a generic user profile
 type User struct {
-	ID        int       `json:"id"`
+	ID        string    `json:"id"`
 	Name      string    `json:"name"`
 	Email     string    `json:"email"`
 	Role      string    `json:"role"`
diff --git a/backend/internal/services/admin_service.go b/backend/internal/services/admin_service.go
index 53b0cc1..3aa56ea 100644
--- a/backend/internal/services/admin_service.go
+++ b/backend/internal/services/admin_service.go
@@ -525,7 +525,7 @@ func (s *AdminService) getTagByID(ctx context.Context, id int) (*models.Tag, err
 }
 
 // GetUser fetches a user by ID
-func (s *AdminService) GetUser(ctx context.Context, id int) (*dto.User, error) {
+func (s *AdminService) GetUser(ctx context.Context, id string) (*dto.User, error) {
 	query := `
 		SELECT id, name, email, role, created_at
 		FROM users WHERE id = $1
@@ -540,7 +540,7 @@ func (s *AdminService) GetUser(ctx context.Context, id int) (*dto.User, error) {
 }
 
 // GetCompanyByUserID fetches the company associated with a user
-func (s *AdminService) GetCompanyByUserID(ctx context.Context, userID int) (*models.Company, error) {
+func (s *AdminService) GetCompanyByUserID(ctx context.Context, userID string) (*models.Company, error) {
 	// First, try to find company where this user is admin
 	// Assuming users table has company_id or companies table has admin_email
 	// Let's check if 'users' has company_id column via error or assume architecture.
@@ -568,7 +568,7 @@ func (s *AdminService) GetCompanyByUserID(ctx context.Context, userID int) (*mod
 			WHERE u.id = $1
 		`
 		if err2 := s.DB.QueryRowContext(ctx, query2, userID).Scan(&c.ID, &c.Name, &c.Slug, &c.Active, &c.Verified); err2 != nil {
-			return nil, fmt.Errorf("company not found for user %d", userID)
+			return nil, fmt.Errorf("company not found for user %s", userID)
 		}
 	}
 	return &c, nil
diff --git a/frontend/src/app/dashboard/backoffice/page.tsx b/frontend/src/app/dashboard/backoffice/page.tsx
index 99a6717..9bf30a1 100644
--- a/frontend/src/app/dashboard/backoffice/page.tsx
+++ b/frontend/src/app/dashboard/backoffice/page.tsx
@@ -91,7 +91,7 @@ export default function BackofficePage() {
         }
     }
 
-    const handleApproveCompany = async (companyId: number) => {
+    const handleApproveCompany = async (companyId: string) => {
         try {
             await adminCompaniesApi.updateStatus(companyId, { verified: true })
             toast.success("Company approved")
@@ -102,7 +102,7 @@ export default function BackofficePage() {
         }
     }
 
-    const handleDeactivateCompany = async (companyId: number) => {
+    const handleDeactivateCompany = async (companyId: string) => {
         try {
             await adminCompaniesApi.updateStatus(companyId, { active: false })
             toast.success("Company deactivated")
@@ -113,7 +113,7 @@ export default function BackofficePage() {
         }
     }
 
-    const handleJobStatus = async (jobId: number, status: string) => {
+    const handleJobStatus = async (jobId: string, status: string) => {
         try {
             await adminJobsApi.updateStatus(jobId, status)
             toast.success("Job status updated")
@@ -124,7 +124,7 @@ export default function BackofficePage() {
         }
     }
 
-    const handleDuplicateJob = async (jobId: number) => {
+    const handleDuplicateJob = async (jobId: string) => {
         try {
             await adminJobsApi.duplicate(jobId)
             toast.success("Job duplicated as draft")
@@ -283,11 +283,11 @@ export default function BackofficePage() {
                                         )}
                                     </TableCell>
                                     <TableCell className="text-right space-x-2">
-                                        <Button size="sm" variant="outline" onClick={() => handleApproveCompany(Number(company.id))}>
+                                        <Button size="sm" variant="outline" onClick={() => handleApproveCompany(company.id)}>
                                             <CheckCircle className="h-4 w-4 mr-2" />
                                             Aprovar
                                         </Button>
-                                        <Button size="sm" variant="destructive" onClick={() => handleDeactivateCompany(Number(company.id))}>
+                                        <Button size="sm" variant="destructive" onClick={() => handleDeactivateCompany(company.id)}>
                                             <XCircle className="h-4 w-4 mr-2" />
                                             Desativar
                                         </Button>
diff --git a/frontend/src/lib/api.ts b/frontend/src/lib/api.ts
index 44c0155..0a6964c 100644
--- a/frontend/src/lib/api.ts
+++ b/frontend/src/lib/api.ts
@@ -87,7 +87,7 @@ export interface AdminCompany {
 }
 
 export interface AdminJob {
-    id: number;
+    id: string;
     title: string;
     companyName: string;
     status: string;
@@ -116,7 +116,7 @@ export interface AdminTag {
 }
 
 export interface AdminCandidate {
-    id: number;
+    id: string;
     name: string;
     email: string;
     phone: string;
@@ -218,12 +218,12 @@ export const adminJobsApi = {
 
         return apiRequest<{ data: AdminJob[]; pagination: any }>(`/api/v1/jobs/moderation?${query.toString()}`);
     },
-    updateStatus: (id: number, status: string) =>
+    updateStatus: (id: string, status: string) =>
         apiRequest<void>(`/api/v1/jobs/${id}/status`, {
             method: "PATCH",
             body: JSON.stringify({ status }),
         }),
-    duplicate: (id: number) =>
+    duplicate: (id: string) =>
         apiRequest<void>(`/api/v1/jobs/${id}/duplicate`, {
             method: "POST",
         }),
@@ -275,14 +275,14 @@ export const adminCompaniesApi = {
             body: JSON.stringify(data),
         });
     },
-    updateStatus: (id: number, data: { active?: boolean; verified?: boolean }) => {
+    updateStatus: (id: string, data: { active?: boolean; verified?: boolean }) => {
         logCrudAction("update", "admin/companies", { id, ...data });
         return apiRequest<void>(`/api/v1/companies/${id}/status`, {
             method: "PATCH",
             body: JSON.stringify(data),
         });
     },
-    delete: (id: number) => {
+    delete: (id: string) => {
         logCrudAction("delete", "admin/companies", { id });
         return apiRequest<void>(`/api/v1/companies/${id}`, {
             method: "DELETE"