5. Database Architecture

• Type: Relational Database (SQL)

* Rationale: Suitable for applications requiring ACID compliance, complex queries, structured data, and strong data integrity.

• Specific Database: PostgreSQL

* Rationale: Open-source, highly reliable, feature-rich, and performant. Supports advanced data types (JSONB) and scales well.

• ORM (Object-Relational Mapper): Prisma

* Rationale: Type-safe ORM that generates a client tailored to your database schema. Simplifies database interactions, provides excellent developer experience with auto-completion, and ensures type safety across the stack (frontend and backend with shared types).

• Schema Design Considerations:

* Normalization: Aim for 3rd Normal Form (3NF) to minimize data redundancy and improve data integrity.

* Indexing: Strategically apply indexes to frequently queried columns to optimize read performance.

* Foreign Keys: Enforce referential integrity between related tables.

* Timestamps: Use createdAt and updatedAt for auditing.

* Soft Deletes: Consider adding deletedAt column for logical deletion instead of physical deletion.

• Migration Strategy: Prisma Migrate for schema evolution and version control.

6. Deployment Architecture

• Cloud Provider: AWS (Amazon Web Services)

* Rationale: Industry leader with a vast array of services, high availability, scalability, and robust security features.

• Containerization: Docker

* Rationale: Encapsulates the application and its dependencies into isolated containers, ensuring consistent environments from development to production.

• Backend Deployment: AWS ECS (Elastic Container Service) with Fargate

* Rationale: Managed container orchestration service. Fargate removes the need to manage EC2 instances, simplifying operations and reducing overhead. Scalable and highly available.

• Frontend Deployment: AWS S3 + CloudFront

* Rationale: Next.js static assets and client-side bundles are deployed to S3, fronted by CloudFront CDN for global content delivery, caching, and improved performance. Next.js SSR/API routes can be deployed to Fargate or AWS Lambda (Next.js Serverless).

• Database Deployment: AWS RDS (Relational Database Service) for PostgreSQL

* Rationale: Managed database service, handling backups, patching, and scaling. Ensures high availability with multi-AZ deployments.

• CI/CD (Continuous Integration/Continuous Deployment): GitHub Actions

* Rationale: Automates the build, test, and deployment process. Triggers on code pushes to specific branches, ensuring rapid and reliable delivery.

* Workflow:

1. Code Commit -> GitHub.

2. GitHub Actions Triggered.

3. Backend: Build Docker image, push to ECR, update ECS service.

4. Frontend: Build static assets, upload to S3, invalidate CloudFront cache.

5. Database: Run Prisma migrations (carefully orchestrated).

• Monitoring & Logging:

* Logs: Centralized logging to AWS CloudWatch Logs.

* Monitoring: AWS CloudWatch Metrics for infrastructure and application performance. Consider integrating with external APM tools like Datadog or New Relic for deeper insights.

7. Authentication & Authorization Strategy

• Strategy: JWT (JSON Web Tokens) with Optional OAuth2 for Third-Party Logins

* User Registration/Login:

1. User registers with email/password (hashed using bcrypt).

2. Upon successful login, the backend issues an access token (JWT) and a refresh token.

3. Access token is short-lived (e.g., 15-60 minutes) and stored in memory (or secure HTTP-only cookie for CSRF protection) on the client.

4. Refresh token is long-lived (e.g., 7-30 days) and stored in an HTTP-only cookie to securely obtain new access tokens.

* Token Management:

* Frontend attaches the access token to Authorization: Bearer <token> header for all authenticated requests.

* Backend validates the JWT signature and expiration on every protected route.

* If access token expires, frontend uses refresh token to get a new pair.

* OAuth2 (e.g., Google, GitHub):

* Integrate Passport.js strategies with NestJS for seamless social logins.

* Upon successful OAuth callback, issue internal JWTs to maintain a consistent authentication mechanism.

• Authorization (RBAC - Role-Based Access Control):

* Define user roles (e.g., Admin, User, Guest).

* Assign roles to users in the database.

* Use NestJS Guards to check user roles against required roles on specific routes or endpoints.

8. Testing Strategy

• Unit Tests:

* Scope: Individual functions, methods, and small isolated components.

* Tools: Jest (Frontend & Backend), React Testing Library (Frontend).

* Coverage Goal: High coverage (e.g., 80%+) for critical business logic and utility functions.

• Integration Tests:

* Scope: Interactions between modules, services, and database. Test API endpoints without full server spin-up.

* Tools: Jest, Supertest (Backend).

* Coverage Goal: Ensure key workflows and data flows work correctly across component boundaries.

• End-to-End (E2E) Tests:

* Scope: Simulate real user scenarios across the full application stack (frontend to backend).

* Tools: Playwright / Cypress.

* Coverage Goal: Cover critical user journeys (e.g., user registration, login, product purchase).

• Linting & Formatting:

* Tools: ESLint, Prettier.

* Integration: Integrated into CI/CD pipeline to ensure code quality and consistency.

9. Key Non-Functional Requirements (NFRs)

• Scalability:

* Backend: Stateless microservices (future-proofing), horizontal scaling of ECS containers, read replicas for PostgreSQL.

* Frontend: CDN caching, SSR/SSG for reduced server load.

• Security:

* OWASP Top 10: Adherence to best practices to mitigate common vulnerabilities (e.g., XSS, CSRF, SQL Injection).

* HTTPS: All communication encrypted with SSL/TLS.

* Data Encryption: At rest (AWS RDS) and in transit.

* Input Validation: Strict validation on all user inputs (frontend and backend).

* Dependency Scanning: Regular checks for known vulnerabilities in third-party libraries.

• Performance:

* Fast Load Times: Achieved through Next.js SSR/SSG, CDN, optimized images.

* Efficient APIs: Optimized database queries, caching strategies (e.g., Redis for frequently accessed data).

* Code Optimization: Bundle splitting, tree shaking.

• Maintainability:

* Clean Code: Adherence to coding standards, linters, and clear documentation.

* Modular Design: Clear separation of concerns in both frontend and backend.

* Automated Tests: Comprehensive test suites to prevent regressions.

* Consistent Tooling: Standardized frameworks and libraries across the stack.

This architectural blueprint provides a solid foundation for your full-stack application. The next steps will involve detailed component design, API specification, and environment setup based on this plan.

Full Stack Application Blueprint: Task Management System

This document provides a comprehensive, detailed, and professional blueprint for a full-stack application, specifically a "Task Management System." This blueprint covers frontend components, backend API, database design, authentication, deployment configuration, and test suites, offering a production-ready foundation ready for development.

Executive Summary

This blueprint outlines a robust and scalable architecture for a modern full-stack application. We've selected a popular and efficient technology stack: React with TypeScript for the frontend, Node.js with Express and TypeScript for the backend, and PostgreSQL as the relational database, managed by Prisma ORM. Authentication is handled via JWTs. The blueprint includes detailed code examples, project structures, and deployment strategies, ensuring a clear path from concept to a deployable product.

1. Project Overview & Core Features (Task Management System)

Application Name: TaskFlow Pro

Description: A web application designed to help users organize, track, and manage their tasks efficiently. Users can create projects, add tasks to projects, set due dates, assign priorities, and mark tasks as complete.

Core Features:

• User Authentication: Register, Login, Logout.
• Project Management:

* Create, Read, Update, Delete (CRUD) projects.

* View projects associated with the logged-in user.

• Task Management:

* Create, Read, Update, Delete (CRUD) tasks within a project.

* Assign tasks to projects.

* Set task priority (Low, Medium, High).

* Set task due dates.

* Mark tasks as completed.

• Dashboard: Overview of upcoming tasks, project summaries.

2. Technology Stack Selection

The chosen technologies offer a balance of performance, developer experience, community support, and scalability.

• Frontend:

* React (with TypeScript): A declarative, component-based UI library, excellent for building complex and interactive user interfaces. TypeScript enhances code quality and maintainability.

* Axios: Promise-based HTTP client for making API requests.

* React Router DOM: For client-side routing.

* Tailwind CSS (Optional but Recommended): A utility-first CSS framework for rapid UI development.

• Backend:

* Node.js (with TypeScript): A powerful JavaScript runtime for building scalable network applications. TypeScript ensures type safety and better code organization.

* Express.js: A fast, unopinionated, minimalist web framework for Node.js.

* Prisma ORM: Modern, type-safe ORM for Node.js and TypeScript, simplifying database interactions and migrations.

* PostgreSQL: Robust, open-source relational database, known for its reliability and feature set.

* JSON Web Tokens (JWT): For secure, stateless user authentication.

* Bcrypt: For secure password hashing.

• Deployment:

* Docker: For containerization, ensuring consistent environments across development and production.

* Docker Compose: For orchestrating multi-container applications locally.

• Testing:

* Jest: A delightful JavaScript Testing Framework with a focus on simplicity.

* Supertest: For testing HTTP APIs with Jest.

3. Database Design

We will use PostgreSQL as the database, managed by Prisma ORM.

3.1. Entity Relationship Diagram (Conceptual)

• User:

* id (PK)

* email (Unique)

* password (Hashed)

* createdAt

* updatedAt

• Project:

* id (PK)

* name

* description

* userId (FK to User)

* createdAt

* updatedAt

• Task:

* id (PK)

* title

* description

* status (Enum: PENDING, IN_PROGRESS, COMPLETED)

* priority (Enum: LOW, MEDIUM, HIGH)

* dueDate

* projectId (FK to Project)

* createdAt

* updatedAt

3.2. Prisma Schema (prisma/schema.prisma)

This schema defines our database models and their relationships.

// prisma/schema.prisma
generator client {
  provider = "prisma-client-js"
}

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

// User Model
model User {
  id        String    @id @default(uuid())
  email     String    @unique
  password  String
  createdAt DateTime  @default(now())
  updatedAt DateTime  @updatedAt
  projects  Project[] // One-to-many relationship with Project

  @@map("users") // Map model name to table name
}

// Project Model
model Project {
  id          String   @id @default(uuid())
  name        String
  description String?
  userId      String   // Foreign key to User
  user        User     @relation(fields: [userId], references: [id], onDelete: Cascade) // Relation to User
  tasks       Task[]   // One-to-many relationship with Task
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt

  @@map("projects")
}

// Task Status Enum
enum TaskStatus {
  PENDING
  IN_PROGRESS
  COMPLETED
}

// Task Priority Enum
enum TaskPriority {
  LOW
  MEDIUM
  HIGH
}

// Task Model
model Task {
  id          String       @id @default(uuid())
  title       String
  description String?
  status      TaskStatus   @default(PENDING)
  priority    TaskPriority @default(MEDIUM)
  dueDate     DateTime?
  projectId   String       // Foreign key to Project
  project     Project      @relation(fields: [projectId], references: [id], onDelete: Cascade) // Relation to Project
  createdAt   DateTime     @default(now())
  updatedAt   DateTime     @updatedAt

  @@map("tasks")
}

Explanation:

• generator client: Specifies that we're generating a Prisma Client for JavaScript/TypeScript.
• datasource db: Defines our database connection using PostgreSQL and an environment variable for the URL.
• User, Project, Task models: Define the structure of our tables.
• @id @default(uuid()): Sets a unique identifier for each record using UUIDs.
• @unique: Ensures the email field is unique for users.
• @relation: Defines the relationships between models (e.g., a User has many Projects). onDelete: Cascade ensures that if a user is deleted, their projects and tasks are also deleted.
• @default(now()), @updatedAt: Automatically manage createdAt and updatedAt timestamps.
• @@map: Customizes the table name in the database.
• enum TaskStatus, enum TaskPriority: Define custom enum types for task status and priority.

3.3. Database Migrations

After defining the schema, Prisma allows generating and applying migrations to keep the database schema in sync with the Prisma schema.

• Generate Migration: npx prisma migrate dev --name init
• Apply Migrations: npx prisma migrate deploy (for production)
• Generate Prisma Client: npx prisma generate (after any schema change)

4. Backend API Blueprint (Node.js/Express/TypeScript)

4.1. Project Structure

backend/
├── src/
│   ├── config/              // Environment variables, constants
│   │   └── index.ts
│   ├── controllers/         // Business logic for routes
│   │   ├── auth.controller.ts
│   │   └── tasks.controller.ts
│   │   └── projects.controller.ts
��   ├── middleware/          // Express middleware (e.g., authentication)
│   │   └── auth.middleware.ts
│   ├── routes/              // API routes definitions
│   │   ├── auth.routes.ts
│   │   └── tasks.routes.ts
│   │   └── projects.routes.ts
│   ├── services/            // Database interaction logic
│   │   ├── auth.service.ts
│   │   └── tasks.service.ts
│   │   └── projects.service.ts
│   ├── utils/               // Helper functions (e.g., JWT, password hashing)
│   │   ├── jwt.ts
│   │   └── password.ts
│   ├── app.ts               // Express application setup
│   └── server.ts            // Entry point for starting the server
├── prisma/                  // Prisma schema and migrations
│   └── schema.prisma
├── .env                     // Environment variables
├── tsconfig.json            // TypeScript configuration
├── package.json             // Project dependencies and scripts
└── Dockerfile               // Docker build instructions

4.2. Core Dependencies (backend/package.json)

{
  "name": "taskflow-pro-backend",
  "version": "1.0.0",
  "description": "Backend API for TaskFlow Pro",
  "main": "dist/server.js",
  "scripts": {
    "start": "node dist/server.js",
    "dev": "nodemon src/server.ts",
    "build": "tsc",
    "prisma:generate": "npx prisma generate",
    "prisma:migrate:dev": "npx prisma migrate dev",
    "prisma:migrate:deploy": "npx prisma migrate deploy",
    "test": "jest --detectOpenHandles --forceExit"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@prisma/client": "^5.x.x",
    "bcryptjs": "^2.4.3",
    "cookie-parser": "^1.4.6",
    "cors": "^2.8.5",
    "dotenv": "^16.4.5",
    "express": "^4.19.2",
    "express-validator": "^7.1.0",
    "helmet": "^7.1.0",
    "jsonwebtoken": "^9.0.2",
    "morgan": "^1.10.0"
  },
  "devDependencies": {
    "@types/bcryptjs": "^2.4.6",
    "@types/cookie-parser": "^1.4.7",
    "@types/cors": "^2.8.17",
    "@types/express": "^4.17.21",
    "@types/jest": "^29.5.12",
    "@types/jsonwebtoken": "^9.0.6",
    "@types/morgan": "^1.9.9",
    "@types/node": "^20.12.12",
    "@types/supertest": "^6.0.2",
    "jest": "^29.7.0",
    "nodemon": "^3.1.0",
    "prisma": "^5.x.x",
    "supertest": "^7.0.0",
    "ts-jest": "^29.1.2",
    "ts-node": "^10.9.2",
    "typescript": "^5.4.5"
  }
}

4.3. Environment Configuration (backend/.env)

# Database
DATABASE_URL="postgresql://user:password@localhost:5432/taskflow_pro_db?schema=public"

# Server
PORT=5000
NODE_ENV=development

# JWT Secret
JWT_SECRET="your_jwt_secret_key_change_this_in_production"
JWT_EXPIRES_IN="1d"

# Frontend Origin (for CORS)
FRONTEND_URL="http://localhost:3000"

4.4. Backend Code Examples

##### backend/src/config/index.ts

// backend/src/config/index.ts
import dotenv from 'dotenv';

dotenv.config();

export const config = {
  port: process.env.PORT || 5000,
  nodeEnv: process.env.NODE_ENV || 'development',
  jwtSecret: process.env.JWT_SECRET || 'supersecretjwtkey',
  jwtExpiresIn: process.env.JWT_EXPIRES_IN || '1d',
  frontendUrl: process.env.FRONTEND_URL || 'http://localhost:3000',
  databaseUrl: process.env.DATABASE_URL || 'postgresql://user:

Full Stack Application Blueprint: Comprehensive Deliverable

This document provides a comprehensive, detailed, and actionable blueprint for a modern full-stack application, covering all essential components from frontend to backend, database, authentication, deployment, and testing. This blueprint is designed to be a ready-to-build specification, enabling your development team to commence implementation with clarity and confidence.

1. Project Overview & Vision

Application Name: (Placeholder - e.g., "Project Management Suite", "E-commerce Platform", "Healthcare Dashboard")

Core Purpose: To provide a robust and scalable platform for [briefly describe the primary function, e.g., "managing tasks and team collaboration", "online sales and inventory", "secure patient data visualization"].

Key Stakeholders: [e.g., "End-users (employees/customers)", "Administrators", "Business Analysts"]

Target Audience: [e.g., "Small to medium-sized businesses", "Individual consumers", "Healthcare professionals"]

High-Level Features:

• User registration and secure login.
• CRUD (Create, Read, Update, Delete) operations for core entities (e.g., tasks, products, patients).
• Role-based access control.
• Responsive user interface across devices.
• Scalable and maintainable backend API.
• Reliable data storage and retrieval.

2. Technology Stack

A modern, robust, and scalable technology stack has been selected to ensure high performance, developer efficiency, and long-term maintainability.

• Frontend:

* Framework: Next.js (React) - For server-side rendering (SSR), static site generation (SSG), API routes, and optimized performance.

* Language: TypeScript - For type safety, improved code quality, and better tooling.

* Styling: Tailwind CSS - For utility-first CSS, rapid UI development, and consistent design.

* State Management: React Context API / Zustand / Redux Toolkit - For global state management, depending on complexity. (Recommendation: Zustand for simplicity, Redux Toolkit for complex apps).

* Data Fetching: React Query / SWR - For efficient data fetching, caching, and synchronization.

• Backend:

* Framework: NestJS (Node.js) - For a highly scalable, maintainable, and enterprise-grade application architecture based on TypeScript.

* Language: TypeScript - Consistent with frontend for full-stack type safety.

* ORM/ODM: TypeORM (for PostgreSQL) - For robust database interaction and schema migrations.

* API Style: RESTful API - Standard, stateless communication.

• Database:

* Primary Database: PostgreSQL - A powerful, open-source relational database known for its reliability, feature set, and ACID compliance.

* Caching (Optional): Redis - For session management, frequently accessed data, and real-time features.

• Authentication:

* Strategy: JSON Web Tokens (JWT) with refresh tokens - For secure, stateless authentication.

* Hashing: BCrypt - For secure password storage.

• Deployment & DevOps:

* Cloud Provider: AWS (Amazon Web Services)

* Containerization: Docker

* CI/CD: GitHub Actions / GitLab CI / AWS CodePipeline

* Infrastructure as Code (IaC): AWS CDK / Terraform (Recommendation: AWS CDK for AWS-native IaC)

• Other Tools:

* Version Control: Git / GitHub

* Package Manager: npm / yarn

* Linting/Formatting: ESLint, Prettier

* Monitoring: AWS CloudWatch, Prometheus/Grafana (for advanced metrics)

* Error Tracking: Sentry

3. Application Architecture

High-Level Architecture Diagram (Conceptual):

graph TD
    A[User Browser/Mobile App] -->|HTTPS| B(CDN - AWS CloudFront)
    B --> C(Next.js Frontend - AWS S3/EC2/ECS)
    C -->|API Calls (HTTPS)| D(Load Balancer - AWS ALB)
    D --> E(NestJS Backend API - AWS ECS/EC2)
    E -->|Database Connection| F(PostgreSQL Database - AWS RDS)
    E -->|Cache Read/Write| G(Redis - AWS ElastiCache)
    E -->|File Storage| H(AWS S3 - Static Assets/Uploads)
    E -->|Auth/Security| I(AWS Cognito / Custom Auth Service)
    SubGraph Deployment
        J(Developer) --> K(Git Repository)
        K --> L(CI/CD Pipeline)
        L --> M(Docker Registry - AWS ECR)
        L --> N(AWS ECS/EC2)
        L --> O(AWS RDS)
    End

Key Architectural Patterns:

• Client-Server Architecture: Frontend consumes RESTful API from the backend.
• Microservices (Optional): While starting with a monolithic NestJS API, the modular nature of NestJS allows for easy decomposition into microservices later if scaling needs dictate.
• Stateless Backend: Backend services do not store session information; user authentication relies on JWTs.
• Event-Driven (Optional): For complex workflows, a message queue (e.g., AWS SQS, Kafka) can be integrated for asynchronous processing.
• Layered Architecture: Clear separation of concerns within the backend (Controllers, Services, Repositories).

4. Frontend Blueprint (Next.js with React & TypeScript)

4.1. UI/UX Principles:

• Responsiveness: Fluid layouts for optimal viewing across desktops, tablets, and mobile devices.
• Accessibility (A11y): Adherence to WCAG guidelines for inclusive design.
• Performance: Fast loading times, optimized images, lazy loading, and efficient data rendering.
• Consistency: A unified design language, component library, and styling approach.
• Intuitiveness: Clear navigation, understandable interactions, and helpful feedback.

4.2. Key Components & Pages (Example Structure):

• Layout Components:

* Layout.tsx: Main application wrapper (Header, Footer, Navigation).

* AuthLayout.tsx: Specific layout for login/signup pages.

* DashboardLayout.tsx: Layout for authenticated user dashboards.

• Navigation Components:

* Header.tsx: Application logo, user profile, global search.

* Sidebar.tsx: Primary navigation for authenticated users.

* Breadcrumbs.tsx: Contextual navigation.

• UI Primitives (Reusable Atoms):

* Button.tsx

* Input.tsx, Textarea.tsx, Select.tsx

* Modal.tsx, Dialog.tsx

* Dropdown.tsx, Tooltip.tsx

* Spinner.tsx, LoadingOverlay.tsx

* Table.tsx, Pagination.tsx

* Alert.tsx, Toast.tsx

• Feature-Specific Components:

* UserCard.tsx, UserProfileForm.tsx

* TaskList.tsx, TaskItem.tsx, TaskForm.tsx

* ProductGrid.tsx, ProductCard.tsx, ProductDetails.tsx

• Pages (Next.js pages directory):

* index.tsx: Homepage/Landing page.

* auth/login.tsx, auth/register.tsx, auth/forgot-password.tsx

* dashboard/index.tsx: Main dashboard for authenticated users.

* dashboard/profile.tsx, dashboard/settings.tsx

* dashboard/tasks/index.tsx, dashboard/tasks/[id].tsx, dashboard/tasks/new.tsx

* 404.tsx, 500.tsx

4.3. State Management:

• Global State: Zustand (lightweight, simple, powerful) or React Context API for application-wide data (e.g., authenticated user info, theme settings).
• Server State: React Query / SWR for managing asynchronous data fetched from the API (caching, revalidation, optimistic updates).
• Local Component State: useState hook for component-specific UI state.
• Form State: React Hook Form or Formik for efficient form handling and validation.

4.4. Routing:

• Next.js File-System Routing: Pages are automatically routed based on their file names in the pages directory.
• Dynamic Routes: pages/posts/[id].tsx for dynamic content.
• Protected Routes: Higher-Order Components (HOCs) or custom hooks to check authentication status and redirect unauthenticated users.

4.5. Data Fetching:

• Server-Side Rendering (SSR): getServerSideProps for pages requiring data to be fetched on each request.
• Static Site Generation (SSG): getStaticProps for pages that can be pre-rendered at build time.
• Client-Side Fetching: React Query / SWR hooks for data that can be loaded after the initial page render or for interactive updates.
• API Routes (Next.js built-in): For simple backend logic or proxying external APIs directly from the Next.js app.

4.6. Styling Strategy:

• Tailwind CSS: Utility-first approach for rapid styling directly in JSX.
• CSS Modules (Optional): For highly specific component styles or overrides.
• PostCSS: For additional CSS processing (e.g., autoprefixer).
• Theming: Centralized tailwind.config.js for design tokens (colors, fonts, spacing). CSS variables for dynamic theme changes (e.g., dark mode).

5. Backend API Blueprint (NestJS with TypeScript)

5.1. API Design Principles:

• RESTful: Resource-oriented, stateless, using standard HTTP methods (GET, POST, PUT, PATCH, DELETE).
• Clear Naming Conventions: Plural nouns for resources (e.g., /users, /products).
• Versioning: Prefix API routes with a version (e.g., /api/v1/users) to allow for future changes without breaking existing clients.
• Idempotency: PUT and DELETE requests should be idempotent.
• Filtering, Sorting, Pagination: Support for common query parameters (e.g., ?limit=10&offset=0&sortBy=createdAt&order=desc&status=active).
• Error Handling: Consistent and informative error responses with appropriate HTTP status codes.

5.2. Key Endpoints (Example with a Task resource):

• Authentication & Authorization:

* POST /api/v1/auth/register: Register a new user.

* POST /api/v1/auth/login: Authenticate user, return JWT and refresh token.

* POST /api/v1/auth/refresh: Refresh access token using refresh token.

* POST /api/v1/auth/logout: Invalidate refresh token.

* POST /api/v1/auth/forgot-password: Initiate password reset.

* POST /api/v1/auth/reset-password: Complete password reset.

• User Management:

* GET /api/v1/users/me: Get current authenticated user's profile. (Auth required)

* PATCH /api/v1/users/me: Update current user's profile. (Auth required)

* GET /api/v1/users/:id: Get user by ID. (Admin/Auth required)

* GET /api/v1/users: Get all users (with pagination/filters). (Admin required)

• Tasks (Example Resource):

* GET /api/v1/tasks: Retrieve a list of tasks (with pagination, filtering by status, assignedTo, etc.).

* Example Query: /api/v1/tasks?status=pending&limit=10&offset=0

* GET /api/v1/tasks/:id: Retrieve a specific task by ID.

* POST /api/v1/tasks: Create a new task.

* Request Body: { "title": "...", "description": "...", "status": "...", "dueDate": "...", "assignedToId": "..." }

* PUT /api/v1/tasks/:id: Replace an existing task by ID.

* PATCH /api/v1/tasks/:id: Partially update an existing task by ID.

* Request Body: { "status": "completed" }

* DELETE /api/v1/tasks/:id: Delete a task by ID.

5.3. Data Models (Backend Perspective - NestJS DTOs & TypeORM Entities):

• User Entity:

* id (UUID)

* email (string, unique)

* password (string, hashed)

* firstName (string)

* lastName (string)

* role (enum: ADMIN, USER, GUEST)

* createdAt (Date)

* updatedAt (Date)

* refreshToken (string, encrypted, nullable - for refresh token rotation)

• Task Entity:

* id (UUID)

* title (string)

* description (string, nullable)

* status (enum: TODO, IN_PROGRESS, DONE, BLOCKED)

* priority (enum: LOW, MEDIUM, HIGH)

* dueDate (Date, nullable)

* assignedTo (Relation to User entity)

* createdBy (Relation to User entity)

* createdAt (Date)

* updatedAt (Date)

5.4. Business Logic Overview:

• Services Layer: Contains the core business logic, orchestrating interactions between controllers and repositories.

* AuthService: Handles user registration, login, token generation, password resets.

* UserService: Manages user profiles, role assignments.

* TaskService: Implements task creation, updates, status changes, assignments, and validation.

• Validation: Joi or Class Validator (NestJS native) for request payload validation.
• Error Handling: Global exception filters to catch and