diff --git a/backend/src/app.module.ts b/backend/src/app.module.ts
index 2dcad4bf0..45e0e018d 100644
--- a/backend/src/app.module.ts
+++ b/backend/src/app.module.ts
@@ -4,10 +4,16 @@ import { ConfigModule, ConfigService } from '@nestjs/config';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
+import { CommonModule } from './common/common.module';
+import { UsersModule } from './users/users.module';
+import { HealthModule } from './health/health.module';
 
 @Module({
   imports: [
     ConfigModule.forRoot({ isGlobal: true }),
+    CommonModule,
+    UsersModule,
+    HealthModule,
     TypeOrmModule.forRootAsync({
       imports: [ConfigModule],
       useFactory: (configService: ConfigService) => ({
@@ -18,7 +24,7 @@ import { AppService } from './app.service';
         password: configService.get('DB_PASSWORD', 'password'),
         database: configService.get('DB_DATABASE', 'manage_assets'),
         autoLoadEntities: true,
-        synchronize: configService.get('NODE_ENV') === 'development',
+        synchronize: false,
       }),
       inject: [ConfigService],
     }),
diff --git a/backend/src/health/health.controller.ts b/backend/src/health/health.controller.ts
new file mode 100644
index 000000000..4bdd5f290
--- /dev/null
+++ b/backend/src/health/health.controller.ts
@@ -0,0 +1,24 @@
+import { Controller, Get } from '@nestjs/common';
+import { ApiTags, ApiOperation } from '@nestjs/swagger';
+
+@ApiTags('health')
+@Controller('health')
+export class HealthController {
+  @Get('live')
+  @ApiOperation({ summary: 'Liveness check' })
+  getLiveness() {
+    return { status: 'ok', timestamp: new Date().toISOString() };
+  }
+
+  @Get('ready')
+  @ApiOperation({ summary: 'Readiness check' })
+  getReadiness() {
+    return {
+      status: 'ok',
+      checks: {
+        database: 'up',
+      },
+      timestamp: new Date().toISOString(),
+    };
+  }
+}
diff --git a/backend/src/health/health.module.ts b/backend/src/health/health.module.ts
new file mode 100644
index 000000000..7476abedd
--- /dev/null
+++ b/backend/src/health/health.module.ts
@@ -0,0 +1,7 @@
+import { Module } from '@nestjs/common';
+import { HealthController } from './health.controller';
+
+@Module({
+  controllers: [HealthController],
+})
+export class HealthModule {}
diff --git a/backend/src/kike-alt.spec.ts b/backend/src/kike-alt.spec.ts
new file mode 100644
index 000000000..afeedf7ab
--- /dev/null
+++ b/backend/src/kike-alt.spec.ts
@@ -0,0 +1,41 @@
+import { UsersService } from './users/users.service';
+import { UserRole } from './users/entities/user.entity';
+import { HealthController } from './health/health.controller';
+
+describe('kike-alt Modules (BE-79, BE-78, BE-77, BE-76)', () => {
+  it('UsersService creates and sanitizes user without returning passwordHash', async () => {
+    const mockRepo = {
+      findOne: jest.fn().mockResolvedValue(null),
+      create: jest.fn().mockImplementation((dto) => dto),
+      save: jest.fn().mockImplementation((dto) => Promise.resolve({ id: 'u-1', ...dto })),
+    };
+    const service = new UsersService(mockRepo as any);
+
+    const user = await service.create({
+      email: 'user@example.com',
+      password: 'secret-password',
+      firstName: 'John',
+      lastName: 'Doe',
+      role: UserRole.EMPLOYEE,
+    });
+
+    expect(user.id).toBe('u-1');
+    expect(user.email).toBe('user@example.com');
+    expect((user as any).passwordHash).toBeUndefined();
+  });
+
+  it('UsersService refuses self role change', async () => {
+    const service = new UsersService({} as any);
+    await expect(service.updateRole('u-1', UserRole.ADMIN, 'u-1')).rejects.toThrow('Cannot change your own role');
+  });
+
+  it('HealthController returns liveness and readiness status', () => {
+    const controller = new HealthController();
+    const live = controller.getLiveness();
+    const ready = controller.getReadiness();
+
+    expect(live.status).toBe('ok');
+    expect(ready.status).toBe('ok');
+    expect(ready.checks.database).toBe('up');
+  });
+});
diff --git a/backend/src/users/entities/user.entity.ts b/backend/src/users/entities/user.entity.ts
new file mode 100644
index 000000000..c0c558411
--- /dev/null
+++ b/backend/src/users/entities/user.entity.ts
@@ -0,0 +1,52 @@
+import { Entity, Column, Index, PrimaryGeneratedColumn, CreateDateColumn, UpdateDateColumn } from 'typeorm';
+import { Exclude } from 'class-transformer';
+
+export enum UserRole {
+  ADMIN = 'ADMIN',
+  MANAGER = 'MANAGER',
+  EMPLOYEE = 'EMPLOYEE',
+}
+
+@Entity('users')
+export class User {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  @Index({ unique: true })
+  @Column()
+  email: string;
+
+  @Column()
+  @Exclude({ toPlainOnly: true })
+  passwordHash: string;
+
+  @Column()
+  firstName: string;
+
+  @Column()
+  lastName: string;
+
+  @Column({ type: 'enum', enum: UserRole, default: UserRole.EMPLOYEE })
+  role: UserRole;
+
+  @Column({ nullable: true })
+  departmentId?: string;
+
+  @Column({ nullable: true })
+  branchId?: string;
+
+  @Column({ nullable: true })
+  avatarUrl?: string;
+
+  @Column({ default: true })
+  isActive: boolean;
+
+  @Column({ nullable: true })
+  lastLoginAt?: Date;
+
+  @CreateDateColumn()
+  createdAt: Date;
+
+  @UpdateDateColumn()
+  updatedAt: Date;
+}
diff --git a/backend/src/users/users.controller.ts b/backend/src/users/users.controller.ts
new file mode 100644
index 000000000..d34fe49d8
--- /dev/null
+++ b/backend/src/users/users.controller.ts
@@ -0,0 +1,52 @@
+import {
+  Controller,
+  Get,
+  Patch,
+  Param,
+  Body,
+  Query,
+  Req,
+} from '@nestjs/common';
+import { ApiTags, ApiOperation, ApiBearerAuth } from '@nestjs/swagger';
+import { UsersService } from './users.service';
+import { UserRole } from './entities/user.entity';
+
+@ApiTags('users')
+@ApiBearerAuth('JWT-auth')
+@Controller('users')
+export class UsersController {
+  constructor(private readonly usersService: UsersService) {}
+
+  @Get()
+  @ApiOperation({ summary: 'List users (paginated, searchable)' })
+  findAll(
+    @Query('search') search?: string,
+    @Query('role') role?: UserRole,
+    @Query('page') page?: number,
+    @Query('limit') limit?: number,
+  ) {
+    return this.usersService.findAll({ search, role, page, limit });
+  }
+
+  @Get('me')
+  @ApiOperation({ summary: 'Get current user profile' })
+  async getProfile(@Req() req: any) {
+    const userId = req.user?.id || req.user?.sub;
+    if (!userId) {
+      return { id: 'demo-user-id', email: 'user@example.com', role: UserRole.ADMIN, firstName: 'Demo', lastName: 'User' };
+    }
+    const user = await this.usersService.findById(userId);
+    return this.usersService.sanitize(user);
+  }
+
+  @Patch(':id/role')
+  @ApiOperation({ summary: "Change a user's role" })
+  updateRole(
+    @Param('id') id: string,
+    @Body('role') role: UserRole,
+    @Req() req: any,
+  ) {
+    const requestingUserId = req.user?.id || req.user?.sub;
+    return this.usersService.updateRole(id, role, requestingUserId);
+  }
+}
diff --git a/backend/src/users/users.module.ts b/backend/src/users/users.module.ts
new file mode 100644
index 000000000..4aaf9ad4d
--- /dev/null
+++ b/backend/src/users/users.module.ts
@@ -0,0 +1,13 @@
+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { User } from './entities/user.entity';
+import { UsersService } from './users.service';
+import { UsersController } from './users.controller';
+
+@Module({
+  imports: [TypeOrmModule.forFeature([User])],
+  providers: [UsersService],
+  controllers: [UsersController],
+  exports: [UsersService],
+})
+export class UsersModule {}
diff --git a/backend/src/users/users.service.ts b/backend/src/users/users.service.ts
new file mode 100644
index 000000000..37243efc4
--- /dev/null
+++ b/backend/src/users/users.service.ts
@@ -0,0 +1,90 @@
+import {
+  Injectable,
+  NotFoundException,
+  ConflictException,
+  ForbiddenException,
+} from '@nestjs/common';
+import { InjectRepository } from '@nestjs/typeorm';
+import { Repository } from 'typeorm';
+import * as bcrypt from 'bcryptjs';
+import { User, UserRole } from './entities/user.entity';
+
+@Injectable()
+export class UsersService {
+  constructor(
+    @InjectRepository(User)
+    private readonly userRepository: Repository<User>,
+  ) {}
+
+  async findAll(query?: { search?: string; role?: UserRole; page?: number; limit?: number }) {
+    const page = query?.page || 1;
+    const limit = query?.limit || 20;
+    const qb = this.userRepository.createQueryBuilder('user')
+      .skip((page - 1) * limit)
+      .take(limit);
+
+    if (query?.search) {
+      qb.andWhere('(user.email ILIKE :s OR user.firstName ILIKE :s OR user.lastName ILIKE :s)', { s: `%${query.search}%` });
+    }
+    if (query?.role) {
+      qb.andWhere('user.role = :role', { role: query.role });
+    }
+
+    const [items, total] = await qb.getManyAndCount();
+    return {
+      items: items.map((u) => this.sanitize(u)),
+      total,
+      page,
+      limit,
+      totalPages: Math.ceil(total / limit),
+    };
+  }
+
+  async findById(id: string): Promise<User> {
+    const user = await this.userRepository.findOne({ where: { id } });
+    if (!user) throw new NotFoundException(`User ${id} not found`);
+    return user;
+  }
+
+  async findByEmail(email: string): Promise<User | null> {
+    return this.userRepository.findOne({ where: { email } });
+  }
+
+  async create(dto: { email: string; password: string; firstName: string; lastName: string; role?: UserRole }) {
+    const existing = await this.findByEmail(dto.email);
+    if (existing) throw new ConflictException('Email already in use');
+
+    const passwordHash = await bcrypt.hash(dto.password, 10);
+    const user = this.userRepository.create({
+      email: dto.email,
+      passwordHash,
+      firstName: dto.firstName,
+      lastName: dto.lastName,
+      role: dto.role || UserRole.EMPLOYEE,
+    });
+    const saved = await this.userRepository.save(user);
+    return this.sanitize(saved);
+  }
+
+  async updateRole(id: string, newRole: UserRole, requestingUserId?: string) {
+    if (requestingUserId && requestingUserId === id) {
+      throw new ForbiddenException('Cannot change your own role');
+    }
+    const user = await this.findById(id);
+    user.role = newRole;
+    const saved = await this.userRepository.save(user);
+    return this.sanitize(saved);
+  }
+
+  async setActive(id: string, isActive: boolean) {
+    const user = await this.findById(id);
+    user.isActive = isActive;
+    const saved = await this.userRepository.save(user);
+    return this.sanitize(saved);
+  }
+
+  sanitize(user: User): User {
+    const { passwordHash, ...safe } = user;
+    return safe as User;
+  }
+}