diff --git a/backend/internal/api/handlers/core_handlers_test.go b/backend/internal/api/handlers/core_handlers_test.go
new file mode 100644
index 0000000..cb71882
--- /dev/null
+++ b/backend/internal/api/handlers/core_handlers_test.go
@@ -0,0 +1,175 @@
+package handlers_test
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/rede5/gohorsejobs/backend/internal/api/handlers"
+	"github.com/rede5/gohorsejobs/backend/internal/core/dto"
+	auth "github.com/rede5/gohorsejobs/backend/internal/core/usecases/auth"
+	tenant "github.com/rede5/gohorsejobs/backend/internal/core/usecases/tenant"
+	user "github.com/rede5/gohorsejobs/backend/internal/core/usecases/user"
+)
+
+// --- Mock Implementations ---
+
+type mockUserRepo struct {
+	saveFunc        func(user interface{}) (interface{}, error)
+	findByEmailFunc func(email string) (interface{}, error)
+}
+
+func (m *mockUserRepo) Save(ctx interface{}, user interface{}) (interface{}, error) {
+	if m.saveFunc != nil {
+		return m.saveFunc(user)
+	}
+	return user, nil
+}
+
+func (m *mockUserRepo) FindByEmail(ctx interface{}, email string) (interface{}, error) {
+	if m.findByEmailFunc != nil {
+		return m.findByEmailFunc(email)
+	}
+	return nil, nil
+}
+
+func (m *mockUserRepo) FindByID(ctx interface{}, id string) (interface{}, error) { return nil, nil }
+func (m *mockUserRepo) FindAllByTenant(ctx interface{}, tenantID string, l, o int) ([]interface{}, int, error) {
+	return nil, 0, nil
+}
+func (m *mockUserRepo) Update(ctx interface{}, user interface{}) (interface{}, error) {
+	return nil, nil
+}
+func (m *mockUserRepo) Delete(ctx interface{}, id string) error { return nil }
+
+type mockAuthService struct{}
+
+func (m *mockAuthService) HashPassword(password string) (string, error) {
+	return "hashed_" + password, nil
+}
+func (m *mockAuthService) GenerateToken(userID, tenantID string, roles []string) (string, error) {
+	return "mock_token", nil
+}
+func (m *mockAuthService) VerifyPassword(hash, password string) bool { return true }
+func (m *mockAuthService) ValidateToken(token string) (map[string]interface{}, error) {
+	return nil, nil
+}
+
+// --- Test Cases ---
+
+func TestRegisterCandidateHandler_Success(t *testing.T) {
+	// This is a simplified integration test structure
+	// In production, you'd wire up the full dependency injection
+	t.Skip("Integration test requires full DI setup - use unit tests in usecases/auth instead")
+}
+
+func TestRegisterCandidateHandler_InvalidPayload(t *testing.T) {
+	// Create a minimal handler for testing payload validation
+	coreHandlers := createTestCoreHandlers(t)
+	if coreHandlers == nil {
+		t.Skip("Cannot create test handlers - skipping")
+		return
+	}
+
+	// Test with invalid JSON
+	body := bytes.NewBufferString("{invalid json}")
+	req := httptest.NewRequest(http.MethodPost, "/api/v1/auth/register", body)
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+
+	coreHandlers.RegisterCandidate(rec, req)
+
+	if rec.Code != http.StatusBadRequest {
+		t.Errorf("Expected status %d, got %d", http.StatusBadRequest, rec.Code)
+	}
+}
+
+func TestRegisterCandidateHandler_MissingFields(t *testing.T) {
+	coreHandlers := createTestCoreHandlers(t)
+	if coreHandlers == nil {
+		t.Skip("Cannot create test handlers - skipping")
+		return
+	}
+
+	testCases := []struct {
+		name     string
+		payload  dto.RegisterCandidateRequest
+		wantCode int
+	}{
+		{
+			name:     "Missing Email",
+			payload:  dto.RegisterCandidateRequest{Name: "John", Password: "123456"},
+			wantCode: http.StatusBadRequest,
+		},
+		{
+			name:     "Missing Password",
+			payload:  dto.RegisterCandidateRequest{Name: "John", Email: "john@example.com"},
+			wantCode: http.StatusBadRequest,
+		},
+		{
+			name:     "Missing Name",
+			payload:  dto.RegisterCandidateRequest{Email: "john@example.com", Password: "123456"},
+			wantCode: http.StatusBadRequest,
+		},
+		{
+			name:     "All Empty",
+			payload:  dto.RegisterCandidateRequest{},
+			wantCode: http.StatusBadRequest,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			body, _ := json.Marshal(tc.payload)
+			req := httptest.NewRequest(http.MethodPost, "/api/v1/auth/register", bytes.NewBuffer(body))
+			req.Header.Set("Content-Type", "application/json")
+			rec := httptest.NewRecorder()
+
+			coreHandlers.RegisterCandidate(rec, req)
+
+			if rec.Code != tc.wantCode {
+				t.Errorf("Expected status %d, got %d", tc.wantCode, rec.Code)
+			}
+		})
+	}
+}
+
+func TestLoginHandler_InvalidPayload(t *testing.T) {
+	coreHandlers := createTestCoreHandlers(t)
+	if coreHandlers == nil {
+		t.Skip("Cannot create test handlers - skipping")
+		return
+	}
+
+	body := bytes.NewBufferString("{invalid}")
+	req := httptest.NewRequest(http.MethodPost, "/api/v1/auth/login", body)
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+
+	coreHandlers.Login(rec, req)
+
+	if rec.Code != http.StatusBadRequest {
+		t.Errorf("Expected status %d, got %d", http.StatusBadRequest, rec.Code)
+	}
+}
+
+// createTestCoreHandlers creates handlers with nil usecases for basic validation tests
+// For full integration tests, wire up real mock implementations
+func createTestCoreHandlers(t *testing.T) *handlers.CoreHandlers {
+	t.Helper()
+
+	// Return nil - these tests need proper DI which we skip for now
+	// The real tests are in usecases/auth package
+	return handlers.NewCoreHandlers(
+		(*auth.LoginUseCase)(nil),
+		(*auth.RegisterCandidateUseCase)(nil),
+		(*tenant.CreateCompanyUseCase)(nil),
+		(*user.CreateUserUseCase)(nil),
+		(*user.ListUsersUseCase)(nil),
+		(*user.DeleteUserUseCase)(nil),
+		(*tenant.ListCompaniesUseCase)(nil),
+		nil, // auditService
+	)
+}
diff --git a/backend/internal/core/usecases/auth/register_candidate.go b/backend/internal/core/usecases/auth/register_candidate.go
index 2f6901e..c2226f9 100644
--- a/backend/internal/core/usecases/auth/register_candidate.go
+++ b/backend/internal/core/usecases/auth/register_candidate.go
@@ -3,6 +3,7 @@ package auth
 import (
 	"context"
 	"errors"
+	"fmt"
 
 	"github.com/google/uuid"
 	"github.com/rede5/gohorsejobs/backend/internal/core/domain/entity"
@@ -12,12 +13,14 @@ import (
 
 type RegisterCandidateUseCase struct {
 	userRepo    ports.UserRepository
+	companyRepo ports.CompanyRepository
 	authService ports.AuthService
 }
 
-func NewRegisterCandidateUseCase(uRepo ports.UserRepository, auth ports.AuthService) *RegisterCandidateUseCase {
+func NewRegisterCandidateUseCase(uRepo ports.UserRepository, cRepo ports.CompanyRepository, auth ports.AuthService) *RegisterCandidateUseCase {
 	return &RegisterCandidateUseCase{
 		userRepo:    uRepo,
+		companyRepo: cRepo,
 		authService: auth,
 	}
 }
@@ -35,10 +38,21 @@ func (uc *RegisterCandidateUseCase) Execute(ctx context.Context, input dto.Regis
 		return nil, err
 	}
 
-	// 3. Create Entity
-	// Candidates belong to their own tenant/workspace in this model logic
+	// 3. Create Candidate's Personal Tenant/Workspace
 	candidateTenantID := uuid.New().String()
+	candidateCompany := entity.NewCompany(
+		candidateTenantID,
+		fmt.Sprintf("Candidate - %s", input.Name),
+		nil, // No document for candidates
+		nil, // No contact - will use user's contact info
+	)
 
+	_, err = uc.companyRepo.Save(ctx, candidateCompany)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create candidate workspace: %w", err)
+	}
+
+	// 4. Create User Entity
 	user := entity.NewUser(uuid.New().String(), candidateTenantID, input.Name, input.Email)
 	user.PasswordHash = hashed
 
diff --git a/backend/internal/core/usecases/auth/register_candidate_test.go b/backend/internal/core/usecases/auth/register_candidate_test.go
index 7c71498..dd95582 100644
--- a/backend/internal/core/usecases/auth/register_candidate_test.go
+++ b/backend/internal/core/usecases/auth/register_candidate_test.go
@@ -39,6 +39,27 @@ func (m *MockUserRepo) Update(ctx context.Context, user *entity.User) (*entity.U
 }
 func (m *MockUserRepo) Delete(ctx context.Context, id string) error { return nil }
 
+type MockCompanyRepo struct {
+	SaveFunc func(ctx context.Context, company *entity.Company) (*entity.Company, error)
+}
+
+func (m *MockCompanyRepo) Save(ctx context.Context, company *entity.Company) (*entity.Company, error) {
+	if m.SaveFunc != nil {
+		return m.SaveFunc(ctx, company)
+	}
+	return company, nil
+}
+func (m *MockCompanyRepo) FindByID(ctx context.Context, id string) (*entity.Company, error) {
+	return nil, nil
+}
+func (m *MockCompanyRepo) FindAll(ctx context.Context) ([]*entity.Company, error) {
+	return nil, nil
+}
+func (m *MockCompanyRepo) Update(ctx context.Context, company *entity.Company) (*entity.Company, error) {
+	return nil, nil
+}
+func (m *MockCompanyRepo) Delete(ctx context.Context, id string) error { return nil }
+
 type MockAuthService struct {
 	HashPasswordFunc  func(password string) (string, error)
 	GenerateTokenFunc func(userID, tenantID string, roles []string) (string, error)
@@ -65,7 +86,7 @@ func (m *MockAuthService) ValidateToken(token string) (map[string]interface{}, e
 
 func TestRegisterCandidateUseCase_Execute(t *testing.T) {
 	t.Run("Success", func(t *testing.T) {
-		repo := &MockUserRepo{
+		userRepo := &MockUserRepo{
 			FindByEmailFunc: func(ctx context.Context, email string) (*entity.User, error) {
 				return nil, nil // Email not found
 			},
@@ -74,9 +95,10 @@ func TestRegisterCandidateUseCase_Execute(t *testing.T) {
 				return user, nil
 			},
 		}
+		companyRepo := &MockCompanyRepo{}
 		authSvc := &MockAuthService{}
 
-		uc := auth.NewRegisterCandidateUseCase(repo, authSvc)
+		uc := auth.NewRegisterCandidateUseCase(userRepo, companyRepo, authSvc)
 
 		input := dto.RegisterCandidateRequest{
 			Name:     "John Doe",
@@ -103,13 +125,14 @@ func TestRegisterCandidateUseCase_Execute(t *testing.T) {
 	})
 
 	t.Run("EmailAlreadyExists", func(t *testing.T) {
-		repo := &MockUserRepo{
+		userRepo := &MockUserRepo{
 			FindByEmailFunc: func(ctx context.Context, email string) (*entity.User, error) {
 				return &entity.User{ID: "existing"}, nil // Found
 			},
 		}
+		companyRepo := &MockCompanyRepo{}
 		authSvc := &MockAuthService{}
-		uc := auth.NewRegisterCandidateUseCase(repo, authSvc)
+		uc := auth.NewRegisterCandidateUseCase(userRepo, companyRepo, authSvc)
 
 		_, err := uc.Execute(context.Background(), dto.RegisterCandidateRequest{Email: "exists@example.com", Password: "123"})
 
@@ -124,14 +147,15 @@ func TestRegisterCandidateUseCase_Execute(t *testing.T) {
 	t.Run("MetadataSaved", func(t *testing.T) {
 		// Verify if username/phone ends up in metadata
 		var capturedUser *entity.User
-		repo := &MockUserRepo{
+		userRepo := &MockUserRepo{
 			SaveFunc: func(ctx context.Context, user *entity.User) (*entity.User, error) {
 				capturedUser = user
 				return user, nil
 			},
 		}
+		companyRepo := &MockCompanyRepo{}
 		authSvc := &MockAuthService{}
-		uc := auth.NewRegisterCandidateUseCase(repo, authSvc)
+		uc := auth.NewRegisterCandidateUseCase(userRepo, companyRepo, authSvc)
 
 		uc.Execute(context.Background(), dto.RegisterCandidateRequest{Username: "coder", Phone: "999"})
 
@@ -145,4 +169,26 @@ func TestRegisterCandidateUseCase_Execute(t *testing.T) {
 			t.Errorf("Expected metadata phone '999', got %v", capturedUser.Metadata["phone"])
 		}
 	})
+
+	t.Run("CompanyCreatedForCandidate", func(t *testing.T) {
+		var capturedCompany *entity.Company
+		userRepo := &MockUserRepo{}
+		companyRepo := &MockCompanyRepo{
+			SaveFunc: func(ctx context.Context, company *entity.Company) (*entity.Company, error) {
+				capturedCompany = company
+				return company, nil
+			},
+		}
+		authSvc := &MockAuthService{}
+		uc := auth.NewRegisterCandidateUseCase(userRepo, companyRepo, authSvc)
+
+		uc.Execute(context.Background(), dto.RegisterCandidateRequest{Name: "Test User", Email: "test@test.com", Password: "123"})
+
+		if capturedCompany == nil {
+			t.Fatal("Company not created")
+		}
+		if capturedCompany.Name != "Candidate - Test User" {
+			t.Errorf("Expected company name 'Candidate - Test User', got %s", capturedCompany.Name)
+		}
+	})
 }
diff --git a/backend/internal/router/router.go b/backend/internal/router/router.go
index 2dfa718..a251de2 100755
--- a/backend/internal/router/router.go
+++ b/backend/internal/router/router.go
@@ -50,7 +50,7 @@ func NewRouter() http.Handler {
 
 	// UseCases
 	loginUC := authUC.NewLoginUseCase(userRepo, authService)
-	registerCandidateUC := authUC.NewRegisterCandidateUseCase(userRepo, authService)
+	registerCandidateUC := authUC.NewRegisterCandidateUseCase(userRepo, companyRepo, authService)
 	createCompanyUC := tenantUC.NewCreateCompanyUseCase(companyRepo, userRepo, authService)
 	listCompaniesUC := tenantUC.NewListCompaniesUseCase(companyRepo)
 	createUserUC := userUC.NewCreateUserUseCase(userRepo, authService)
diff --git a/frontend/src/app/jobs/[id]/page.tsx b/frontend/src/app/jobs/[id]/page.tsx
index 6fbcfc8..d024c94 100644
--- a/frontend/src/app/jobs/[id]/page.tsx
+++ b/frontend/src/app/jobs/[id]/page.tsx
@@ -1,6 +1,6 @@
 "use client";
 
-import { use } from "react";
+import { use, useState, useEffect } from "react";
 import { useRouter } from "next/navigation";
 import { Navbar } from "@/components/navbar";
 import { Footer } from "@/components/footer";
@@ -15,7 +15,7 @@ import {
 import { Badge } from "@/components/ui/badge";
 import { Avatar, AvatarFallback, AvatarImage } from "@/components/ui/avatar";
 import { Separator } from "@/components/ui/separator";
-import { mockJobs } from "@/lib/mock-data";
+import { jobsApi, transformJob, type Job } from "@/lib/api";
 import {
   MapPin,
   Briefcase,
@@ -31,9 +31,9 @@ import {
   Bookmark,
   Star,
   Globe,
+  Loader2,
 } from "lucide-react";
 import Link from "next/link";
-import { useState } from "react";
 import { motion } from "framer-motion";
 
 
@@ -48,8 +48,44 @@ export default function JobDetailPage({
   const router = useRouter();
   const [isFavorited, setIsFavorited] = useState(false);
   const [isBookmarked, setIsBookmarked] = useState(false);
+  const [job, setJob] = useState<Job | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
 
-  const job = mockJobs.find((j) => j.id === id);
+  useEffect(() => {
+    async function fetchJob() {
+      try {
+        setLoading(true);
+        const response = await jobsApi.getById(id);
+        if (response.data) {
+          setJob(transformJob(response.data));
+        } else {
+          setError("Job not found");
+        }
+      } catch (err) {
+        console.error("Error fetching job:", err);
+        setError("Failed to load job");
+      } finally {
+        setLoading(false);
+      }
+    }
+    fetchJob();
+  }, [id]);
+
+  if (loading) {
+    return (
+      <div className="min-h-screen flex flex-col">
+        <Navbar />
+        <main className="flex-1 flex items-center justify-center">
+          <div className="text-center">
+            <Loader2 className="w-8 h-8 animate-spin mx-auto mb-4 text-primary" />
+            <p className="text-muted-foreground">Loading job...</p>
+          </div>
+        </main>
+        <Footer />
+      </div>
+    );
+  }
 
   if (!job) {
     return (
@@ -189,8 +225,8 @@ export default function JobDetailPage({
                                 >
                                   <Heart
                                     className={`h-4 w-4 ${isFavorited
-                                        ? "fill-red-500 text-red-500"
-                                        : ""
+                                      ? "fill-red-500 text-red-500"
+                                      : ""
                                       }`}
                                   />
                                 </Button>
@@ -220,8 +256,8 @@ export default function JobDetailPage({
                               >
                                 <Heart
                                   className={`h-4 w-4 mr-1 ${isFavorited
-                                      ? "fill-red-500 text-red-500"
-                                      : ""
+                                    ? "fill-red-500 text-red-500"
+                                    : ""
                                     }`}
                                 />
                                 {isFavorited ? "Favorited" : "Favorite"}
@@ -486,28 +522,9 @@ export default function JobDetailPage({
                       <CardTitle className="text-lg">Similar jobs</CardTitle>
                     </CardHeader>
                     <CardContent className="space-y-4">
-                      {mockJobs
-                        .filter((j) => j.id !== job.id)
-                        .slice(0, 3)
-                        .map((similarJob) => (
-                          <Link
-                            key={similarJob.id}
-                            href={`/jobs/${similarJob.id}`}
-                          >
-                            <div className="p-3 rounded-lg border hover:bg-muted/50 transition-colors cursor-pointer">
-                              <h4 className="font-medium text-sm mb-1 line-clamp-1">
-                                {similarJob.title}
-                              </h4>
-                              <p className="text-xs text-muted-foreground mb-2">
-                                {similarJob.company}
-                              </p>
-                              <div className="flex items-center gap-2 text-xs text-muted-foreground">
-                                <MapPin className="h-3 w-3" />
-                                <span>{similarJob.location}</span>
-                              </div>
-                            </div>
-                          </Link>
-                        ))}
+                      <p className="text-sm text-muted-foreground">
+                        Find more opportunities like this one.
+                      </p>
                       <Link href="/jobs">
                         <Button variant="outline" size="sm" className="w-full">
                           View all jobs
diff --git a/frontend/src/app/register/company/page.tsx b/frontend/src/app/register/company/page.tsx
index 75a2c62..048f116 100644
--- a/frontend/src/app/register/company/page.tsx
+++ b/frontend/src/app/register/company/page.tsx
@@ -88,22 +88,32 @@ export default function CompanyRegisterPage() {
   const acceptTerms = watch("acceptTerms");
   const acceptNewsletter = watch("acceptNewsletter");
 
+  const [errorMsg, setErrorMsg] = useState<string | null>(null);
+
   const onSubmit = async (data: CompanyFormData) => {
     setLoading(true);
+    setErrorMsg(null);
     try {
-      // Simulate registration
-      await new Promise(resolve => setTimeout(resolve, 2000));
-      console.log("Company data:", data);
+      const { registerCompany } = await import("@/lib/auth");
+
+      await registerCompany({
+        companyName: data.companyName,
+        cnpj: data.cnpj,
+        email: data.email,
+        phone: data.phone,
+      });
 
       // Redirect to login after registration
-      router.push("/login?message=Registration completed successfully! Please sign in to continue.");
-    } catch (error) {
+      router.push("/login?message=Empresa registrada com sucesso! Faça login com seu email e a senha padrão: ChangeMe123!");
+    } catch (error: any) {
       console.error("Registration error:", error);
+      setErrorMsg(error.message || "Erro ao registrar empresa. Tente novamente.");
     } finally {
       setLoading(false);
     }
   };
 
+
   const nextStep = () => {
     if (currentStep < 3) setCurrentStep(currentStep + 1);
   };
diff --git a/frontend/src/lib/__tests__/auth.test.ts b/frontend/src/lib/__tests__/auth.test.ts
new file mode 100644
index 0000000..dc1bf72
--- /dev/null
+++ b/frontend/src/lib/__tests__/auth.test.ts
@@ -0,0 +1,215 @@
+import { RegisterCandidateData } from '../auth';
+
+// Mock fetch globally
+const mockFetch = jest.fn();
+global.fetch = mockFetch;
+
+// Mock localStorage
+const localStorageMock = {
+    getItem: jest.fn(),
+    setItem: jest.fn(),
+    removeItem: jest.fn(),
+    clear: jest.fn(),
+};
+Object.defineProperty(window, 'localStorage', { value: localStorageMock });
+
+describe('Auth Module', () => {
+    let authModule: typeof import('../auth');
+
+    beforeEach(() => {
+        jest.resetModules();
+        mockFetch.mockReset();
+        localStorageMock.getItem.mockReset();
+        localStorageMock.setItem.mockReset();
+        localStorageMock.removeItem.mockReset();
+
+        // Re-import the module fresh
+        authModule = require('../auth');
+    });
+
+    describe('registerCandidate', () => {
+        const validData: RegisterCandidateData = {
+            name: 'John Doe',
+            email: 'john@example.com',
+            password: 'password123',
+            username: 'johndoe',
+            phone: '+5511999999999',
+        };
+
+        it('should register candidate successfully', async () => {
+            const mockResponse = {
+                token: 'mock-jwt-token',
+                user: {
+                    id: '123',
+                    name: 'John Doe',
+                    email: 'john@example.com',
+                    roles: ['CANDIDATE'],
+                },
+            };
+
+            mockFetch.mockResolvedValueOnce({
+                ok: true,
+                json: async () => mockResponse,
+            });
+
+            await expect(authModule.registerCandidate(validData)).resolves.not.toThrow();
+
+            expect(mockFetch).toHaveBeenCalledWith(
+                expect.stringContaining('/auth/register'),
+                expect.objectContaining({
+                    method: 'POST',
+                    headers: { 'Content-Type': 'application/json' },
+                    body: JSON.stringify(validData),
+                })
+            );
+        });
+
+        it('should throw error when email already exists', async () => {
+            const errorResponse = { message: 'email already registered' };
+
+            mockFetch.mockResolvedValueOnce({
+                ok: false,
+                status: 409,
+                json: async () => errorResponse,
+            });
+
+            await expect(authModule.registerCandidate(validData)).rejects.toThrow(
+                'email already registered'
+            );
+        });
+
+        it('should throw error with status code when no message provided', async () => {
+            mockFetch.mockResolvedValueOnce({
+                ok: false,
+                status: 500,
+                json: async () => ({}),
+            });
+
+            await expect(authModule.registerCandidate(validData)).rejects.toThrow(
+                'Erro no registro: 500'
+            );
+        });
+
+        it('should handle network errors gracefully', async () => {
+            mockFetch.mockRejectedValueOnce(new Error('Network error'));
+
+            await expect(authModule.registerCandidate(validData)).rejects.toThrow(
+                'Network error'
+            );
+        });
+
+        it('should send all required fields in request body', async () => {
+            mockFetch.mockResolvedValueOnce({
+                ok: true,
+                json: async () => ({}),
+            });
+
+            await authModule.registerCandidate(validData);
+
+            const callArgs = mockFetch.mock.calls[0];
+            const body = JSON.parse(callArgs[1].body);
+
+            expect(body).toEqual({
+                name: 'John Doe',
+                email: 'john@example.com',
+                password: 'password123',
+                username: 'johndoe',
+                phone: '+5511999999999',
+            });
+        });
+    });
+
+    describe('login', () => {
+        it('should login and store user in localStorage', async () => {
+            const mockResponse = {
+                token: 'mock-jwt-token',
+                user: {
+                    id: '123',
+                    name: 'Test User',
+                    email: 'test@example.com',
+                    roles: ['CANDIDATE'],
+                    status: 'active',
+                    created_at: '2023-01-01T00:00:00Z',
+                },
+            };
+
+            mockFetch.mockResolvedValueOnce({
+                ok: true,
+                json: async () => mockResponse,
+            });
+
+            const user = await authModule.login('test@example.com', 'password123');
+
+            expect(user).toBeDefined();
+            expect(user?.email).toBe('test@example.com');
+            expect(localStorageMock.setItem).toHaveBeenCalledWith(
+                'job-portal-auth',
+                expect.any(String)
+            );
+            expect(localStorageMock.setItem).toHaveBeenCalledWith(
+                'auth_token',
+                'mock-jwt-token'
+            );
+        });
+
+        it('should throw error on invalid credentials', async () => {
+            mockFetch.mockResolvedValueOnce({
+                ok: false,
+                status: 401,
+            });
+
+            await expect(
+                authModule.login('test@example.com', 'wrongpassword')
+            ).rejects.toThrow('Credenciais inválidas');
+        });
+    });
+
+    describe('logout', () => {
+        it('should remove auth data from localStorage', () => {
+            authModule.logout();
+
+            expect(localStorageMock.removeItem).toHaveBeenCalledWith('job-portal-auth');
+            expect(localStorageMock.removeItem).toHaveBeenCalledWith('auth_token');
+        });
+    });
+
+    describe('getCurrentUser', () => {
+        it('should return user from localStorage', () => {
+            const storedUser = { id: '123', name: 'Test', email: 'test@test.com', role: 'candidate' };
+            localStorageMock.getItem.mockReturnValueOnce(JSON.stringify(storedUser));
+
+            const user = authModule.getCurrentUser();
+
+            expect(user).toEqual(storedUser);
+        });
+
+        it('should return null when no user stored', () => {
+            localStorageMock.getItem.mockReturnValueOnce(null);
+
+            const user = authModule.getCurrentUser();
+
+            expect(user).toBeNull();
+        });
+    });
+
+    describe('isAdminUser', () => {
+        it('should return true for admin role', () => {
+            const adminUser = { id: '1', name: 'Admin', email: 'a@a.com', role: 'admin', roles: ['admin'] };
+            expect(authModule.isAdminUser(adminUser)).toBe(true);
+        });
+
+        it('should return true for SUPERADMIN in roles array', () => {
+            const superAdmin = { id: '1', name: 'Super', email: 's@s.com', role: 'candidate', roles: ['SUPERADMIN'] };
+            expect(authModule.isAdminUser(superAdmin)).toBe(true);
+        });
+
+        it('should return false for regular candidate', () => {
+            const candidate = { id: '1', name: 'User', email: 'u@u.com', role: 'candidate', roles: ['CANDIDATE'] };
+            expect(authModule.isAdminUser(candidate)).toBe(false);
+        });
+
+        it('should return false for null user', () => {
+            expect(authModule.isAdminUser(null)).toBe(false);
+        });
+    });
+});
diff --git a/frontend/src/lib/api.ts b/frontend/src/lib/api.ts
index 779c9d5..c299125 100644
--- a/frontend/src/lib/api.ts
+++ b/frontend/src/lib/api.ts
@@ -191,7 +191,7 @@ export const jobsApi = {
         return apiRequest<PaginatedResponse<ApiJob>>(`/jobs${queryStr ? `?${queryStr}` : ""}`);
     },
 
-    getById: (id: number) => {
+    getById: (id: string) => {
         logCrudAction("read", "jobs", { id });
         return apiRequest<ApiJob>(`/jobs/${id}`);
     },
diff --git a/frontend/src/lib/auth.ts b/frontend/src/lib/auth.ts
index f5d0a1a..0ca8948 100644
--- a/frontend/src/lib/auth.ts
+++ b/frontend/src/lib/auth.ts
@@ -112,6 +112,8 @@ export interface RegisterCandidateData {
 }
 
 export async function registerCandidate(data: RegisterCandidateData): Promise<void> {
+  console.log('[registerCandidate] Sending request:', { ...data, password: '***' });
+
   const res = await fetch(`${API_URL}/auth/register`, {
     method: "POST",
     headers: {
@@ -122,13 +124,58 @@ export async function registerCandidate(data: RegisterCandidateData): Promise<vo
 
   if (!res.ok) {
     const errorData = await res.json().catch(() => ({}));
+    console.error('[registerCandidate] Error response:', res.status, errorData);
     throw new Error(errorData.message || `Erro no registro: ${res.status}`);
   }
+
+  const responseData = await res.json().catch(() => ({}));
+  console.log('[registerCandidate] Success response:', {
+    ...responseData,
+    token: responseData.token ? '***' : undefined
+  });
 }
 
+
 export function getToken(): string | null {
   if (typeof window !== "undefined") {
     return localStorage.getItem("auth_token");
   }
   return null;
 }
+
+// Company Registration
+export interface RegisterCompanyData {
+  companyName: string;
+  cnpj: string;
+  email: string;
+  phone: string;
+}
+
+export async function registerCompany(data: RegisterCompanyData): Promise<void> {
+  console.log('[registerCompany] Sending request:', data);
+
+  // Map frontend fields to backend DTO
+  const payload = {
+    name: data.companyName,
+    document: data.cnpj,
+    contact: data.phone,
+    admin_email: data.email,
+  };
+
+  const res = await fetch(`${API_URL}/companies`, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+    },
+    body: JSON.stringify(payload),
+  });
+
+  if (!res.ok) {
+    const errorData = await res.json().catch(() => ({}));
+    console.error('[registerCompany] Error response:', res.status, errorData);
+    throw new Error(errorData.message || `Erro no registro: ${res.status}`);
+  }
+
+  const responseData = await res.json().catch(() => ({}));
+  console.log('[registerCompany] Success - Company created:', responseData);
+}