diff --git a/app/src/services/EmployerService.perf.test.ts b/app/src/services/EmployerService.perf.test.ts
new file mode 100644
index 0000000..9d02f4c
--- /dev/null
+++ b/app/src/services/EmployerService.perf.test.ts
@@ -0,0 +1,107 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { EmployerService } from './EmployerService';
+import { supabase } from '@/lib/supabase';
+
+// Mock Supabase client
+vi.mock('@/lib/supabase', () => {
+  const selectMock = vi.fn();
+  const deleteMock = vi.fn();
+  const insertMock = vi.fn();
+  const eqMock = vi.fn();
+  const fromMock = vi.fn();
+
+  // Chaining setup
+  fromMock.mockReturnValue({
+    select: selectMock,
+    delete: deleteMock,
+    insert: insertMock,
+  });
+
+  selectMock.mockReturnValue({
+    eq: eqMock,
+  });
+
+  deleteMock.mockReturnValue({
+    eq: eqMock,
+  });
+
+  // Default response
+  eqMock.mockImplementation(() => Promise.resolve({ data: [], error: null, count: 0 }));
+
+  return {
+    supabase: {
+      from: fromMock,
+    },
+  };
+});
+
+describe('EmployerService Performance Optimization', () => {
+  const mockEmployerId = 'employer-123';
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('should use optimized count query to check for existence', async () => {
+    // Setup mock for having employees (count > 0)
+    // The select implementation should return count: 2
+
+    const eqMock = vi.fn().mockResolvedValue({ data: null, error: null, count: 2 });
+    const selectMock = vi.fn().mockReturnValue({ eq: eqMock });
+    const fromMock = vi.mocked(supabase.from);
+
+    // Reset the mock implementation for this specific test
+    fromMock.mockImplementation((table: string) => {
+      if (table === 'employees') {
+        return {
+          select: selectMock,
+        } as any;
+      }
+      return {
+        delete: vi.fn().mockReturnValue({ eq: vi.fn() }),
+      } as any;
+    });
+
+    // Execute
+    try {
+      await EmployerService.deleteEmployer(mockEmployerId);
+    } catch (e) {
+      // Expected to fail because count > 0
+    }
+
+    // Verify "Good" Behavior (using count)
+    expect(fromMock).toHaveBeenCalledWith('employees');
+    // Expect select('*', { count: 'exact', head: true })
+    expect(selectMock).toHaveBeenCalledWith('*', { count: 'exact', head: true });
+    expect(eqMock).toHaveBeenCalledWith('employer_id', mockEmployerId);
+  });
+
+  it('should proceed to delete employer if count is 0', async () => {
+     // Setup mock for NO employees (count: 0)
+     const eqMockSelect = vi.fn().mockResolvedValue({ data: null, error: null, count: 0 });
+     const selectMock = vi.fn().mockReturnValue({ eq: eqMockSelect });
+
+     const eqMockDelete = vi.fn().mockResolvedValue({ error: null });
+     const deleteMock = vi.fn().mockReturnValue({ eq: eqMockDelete });
+
+     const fromMock = vi.mocked(supabase.from);
+
+     fromMock.mockImplementation((table: string) => {
+       if (table === 'employees') {
+         return { select: selectMock } as any;
+       }
+       if (table === 'employers') {
+         return { delete: deleteMock } as any;
+       }
+       return {} as any;
+     });
+
+     // Execute
+     await EmployerService.deleteEmployer(mockEmployerId);
+
+     // Verify
+     expect(selectMock).toHaveBeenCalledWith('*', { count: 'exact', head: true });
+     expect(deleteMock).toHaveBeenCalled();
+     expect(eqMockDelete).toHaveBeenCalledWith('id', mockEmployerId);
+  });
+});
diff --git a/app/src/services/EmployerService.ts b/app/src/services/EmployerService.ts
index ee0f94d..928c2c2 100644
--- a/app/src/services/EmployerService.ts
+++ b/app/src/services/EmployerService.ts
@@ -136,14 +136,14 @@ export const EmployerService = {
   // 8. Deletar Família (só se não tiver funcionários)
   async deleteEmployer(employerId: string) {
     // Primeiro verifica se tem funcionários
-    const { data: employees, error: checkError } = await supabase
+    const { count, error: checkError } = await supabase
       .from('employees')
-      .select('id')
+      .select('*', { count: 'exact', head: true })
       .eq('employer_id', employerId);
 
     if (checkError) throw checkError;
 
-    if (employees && employees.length > 0) {
+    if (count !== null && count > 0) {
       throw new Error(
         'Não é possível deletar uma família com funcionários. Delete os funcionários primeiro.'
       );